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1. The first maps of κd – the dust mass absorption coefficient – in nearby galaxies, with DustPedia

Author: C J R Clark, P De Vis, M Baes, S Bianchi, V Casasola, L P Cassarà, J I Davies, W Dobbels, S Lianou, I De Looze, R Evans, M Galametz, F Galliano, A P Jones, S C Madden, A V Mosenkov, S Verstocken, S Viaene, E M Xilouris, and N Ysard
Published: 2019
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2. Searching for Anomalous Microwave Emission in nearby galaxies. K-band observations with the Sardinia Radio Telescope

Author: S. Bianchi, M. Murgia, A. Melis, V. Casasola, F. Galliano, F. Govoni, A. P. Jones, S. C. Madden, R. Paladino, F. Salvestrini, E. M. Xilouris, and N. Ysard
Subjects: Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Astrophysics::Solar and Stellar Astrophysics, Astronomy and Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics - Astrophysics of Galaxies, Astrophysics::Galaxy Astrophysics
Abstract: We observed four nearby spiral galaxies (NGC 3627, NGC 4254, NGC 4736 and NGC 5055) in the K band with the 64-m Sardinia Radio Telescope, with the aim of detecting the Anomalous Microwave Emission (AME), a radiation component presumably due to spinning dust grains, observed so far in the Milky Way and in a handful of other galaxies only (most notably, M 31). We mapped the galaxies at 18.6 and 24.6 GHz and studied their global photometry together with other radio-continuum data from the literature, in order to find AME as emission in excess of the synchrotron and thermal components. We only find upper limits for AME. These non-detections, and other upper limits in the literature, are nevertheless consistent with the average AME emissivity from the few detections: it is $\epsilon^\mathrm{AME}_{\mathrm{30~GHz}} = 2.4\pm0.4 \times 10^{-2}$ MJy sr$^{-1}$ (M$_\odot$ pc$^{-2}$)$^{-1}$ in units of dust surface density (equivalently, $1.4\pm0.2 \times 10^{-18}$ Jy sr$^{-1}$ (H cm$^{-2}$)$^{-1}$ in units of H column density). We finally suggest to search for AME in quiescent spirals with relatively low radio luminosity, such as M~31., Comment: A&A Letter, accepted
Published: 2022

3. Constraints on the structure and seasonal variations of Triton’s atmosphere from the 5 October 2017 stellar occultation and previous observations

Author: J. Marques Oliveira, B. Sicardy, A. R. Gomes-Júnior, J. L. Ortiz, D. F. Strobel, T. Bertrand, F. Forget, E. Lellouch, J. Desmars, D. Bérard, A. Doressoundiram, J. Lecacheux, R. Leiva, E. Meza, F. Roques, D. Souami, T. Widemann, P. Santos-Sanz, N. Morales, R. Duffard, E. Fernández-Valenzuela, A. J. Castro-Tirado, F. Braga-Ribas, B. E. Morgado, M. Assafin, J. I. B. Camargo, R. Vieira-Martins, G. Benedetti-Rossi, S. Santos-Filho, M. V. Banda-Huarca, F. Quispe-Huaynasi, C. L. Pereira, F. L. Rommel, G. Margoti, A. Dias-Oliveira, F. Colas, J. Berthier, S. Renner, R. Hueso, S. Pérez-Hoyos, A. Sánchez-Lavega, J. F. Rojas, W. Beisker, M. Kretlow, D. Herald, D. Gault, K.-L. Bath, H.-J. Bode, E. Bredner, K. Guhl, T. V. Haymes, E. Hummel, B. Kattentidt, O. Klös, A. Pratt, B. Thome, C. Avdellidou, K. Gazeas, E. Karampotsiou, L. Tzouganatos, E. Kardasis, A. A. Christou, E. M. Xilouris, I. Alikakos, A. Gourzelas, A. Liakos, V. Charmandaris, M. Jelínek, J. Štrobl, A. Eberle, K. Rapp, B. Gährken, B. Klemt, S. Kowollik, R. Bitzer, M. Miller, G. Herzogenrath, D. Frangenberg, L. Brandis, I. Pütz, V. Perdelwitz, G. M. Piehler, P. Riepe, K. von Poschinger, P. Baruffetti, D. Cenadelli, J.-M. Christille, F. Ciabattari, R. Di Luca, D. Alboresi, G. Leto, R. Zanmar Sanchez, P. Bruno, G. Occhipinti, L. Morrone, L. Cupolino, A. Noschese, A. Vecchione, C. Scalia, R. Lo Savio, G. Giardina, S. Kamoun, R. Barbosa, R. Behrend, M. Spano, E. Bouchet, M. Cottier, L. Falco, S. Gallego, L. Tortorelli, S. Sposetti, J. Sussenbach, F. Van Den Abbeel, P. André, M. Llibre, F. Pailler, J. Ardissone, M. Boutet, J. Sanchez, M. Bretton, A. Cailleau, V. Pic, L. Granier, R. Chauvet, M. Conjat, J. L. Dauvergne, O. Dechambre, P. Delay, M. Delcroix, L. Rousselot, J. Ferreira, P. Machado, P. Tanga, J.-P. Rivet, E. Frappa, M. Irzyk, F. Jabet, M. Kaschinski, A. Klotz, Y. Rieugnie, A. N. Klotz, O. Labrevoir, D. Lavandier, D. Walliang, A. Leroy, S. Bouley, S. Lisciandra, J.-F. Coliac, F. Metz, D. Erpelding, P. Nougayrède, T. Midavaine, M. Miniou, S. Moindrot, P. Morel, B. Reginato, E. Reginato, J. Rudelle, B. Tregon, R. Tanguy, J. David, W. Thuillot, D. Hestroffer, G. Vaudescal, D. Baba Aissa, Z. Grigahcene, D. Briggs, S. Broadbent, P. Denyer, N. J. Haigh, N. Quinn, G. Thurston, S. J. Fossey, C. Arena, M. Jennings, J. Talbot, S. Alonso, A. Román Reche, V. Casanova, E. Briggs, R. Iglesias-Marzoa, J. Abril Ibáñez, M. C. Díaz Martín, H. González, J. L. Maestre García, J. Marchant, I. Ordonez-Etxeberria, P. Martorell, J. Salamero, F. Organero, L. Ana, F. Fonseca, V. Peris, O. Brevia, A. Selva, C. Perello, V. Cabedo, R. Gonçalves, M. Ferreira, F. Marques Dias, A. Daassou, K. Barkaoui, Z. Benkhaldoun, M. Guennoun, J. Chouqar, E. Jehin, C. Rinner, J. Lloyd, M. El Moutamid, C. Lamarche, J. T. Pollock, D. B. Caton, V. Kouprianov, B. W. Timerson, G. Blanchard, B. Payet, A. Peyrot, J.-P. Teng-Chuen-Yu, J. Françoise, B. Mondon, T. Payet, C. Boissel, M. Castets, W. B. Hubbard, R. Hill, H. J. Reitsema, O. Mousis, L. Ball, G. Neilsen, S. Hutcheon, K. Lay, P. Anderson, M. Moy, M. Jonsen, I. Pink, R. Walters, B. Downs, Ministerio de Ciencia e Innovación (España), Junta de Andalucía, European Research Council, European Commission, Fundação para a Ciência e a Tecnologia (Portugal), Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics (LESIA), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Universidade Estadual Paulista Júlio de Mesquita Filho = São Paulo State University (UNESP), Instituto de Astrofísica de Andalucía (IAA), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Johns Hopkins University (JHU), Laboratoire de Météorologie Dynamique (UMR 8539) (LMD), Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-École des Ponts ParisTech (ENPC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Département des Géosciences - ENS Paris, École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Institut Polytechnique des Sciences Avancées (IPSA), Institut de Mécanique Céleste et de Calcul des Ephémérides (IMCCE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Lille-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Observatoire de la Côte d'Azur (OCA), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Comisión Nacional de Investigación y Desarrollo Aeroespacial (CONIDA), Observatorio Astronómico de Moquegua, Florida Space Institute [Orlando] (FSI), University of Central Florida [Orlando] (UCF), Federal University of Technology - Paraná (UTFPR), Observatório Nacional [Rio de Janeiro] (ON), Ministério da Ciência, Tecnologia, Inovações e Comunicações (MCTIC), Universidade Federal do Rio de Janeiro (UFRJ), Polo Educacional Sesc [Rio de Janeiro], Université de Lille, Universidad del Pais Vasco / Euskal Herriko Unibertsitatea [Espagne] (UPV/EHU), International Occultation Timing Association (IOTA), Internationale Amateursternwarte [Mittenwalde] (IAS), Société Astronomique de France (SAF), Institut de recherche en astrophysique et planétologie (IRAP), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Université Paris-Sud - Paris 11 (UP11), Analyse, ingénierie et contrôle des micro-organismes (MICROCOSME), Inria Grenoble - Rhône-Alpes, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Université Grenoble Alpes (UGA), Laboratoire Ondes et Matière d'Aquitaine (LOMA), Université de Bordeaux (UB)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), European Project: 669416,H2020,ERC-2014-ADG,LUCKY STAR(2015), and European Project: 687378,H2020,H2020-COMPET-2015,SBNAF(2016)
Subjects: Earth and Planetary Astrophysics (astro-ph.EP), planets and satellites: atmospheres, planets and satellites: physical evolution, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], photometric [Techniques], FOS: Physical sciences, Astronomy and Astrophysics, methods: data analysis, techniques: photometric, Space and Planetary Science, [SDU]Sciences of the Universe [physics], atmospheres [Planets and satellites], observational [Methods], methods: observational, data analysis [Methods], physical evolution [Planets and satellites], Astrophysics - Earth and Planetary Astrophysics
Abstract: J.M.O. acknowledges financial support from the Portuguese Foundation for Science and Technology (FCT) and the European Social Fund (ESF) through the PhD grant SFRH/BD/131700/2017. The work leading to these results has received funding from the European Research Council under the European Community's H2020 2014-2021 ERC grant Agreement nffi 669416 "Lucky Star". We thank S. Para who supported some travels to observe the 5 October 2017 occultation. T.B. was supported for this research by an appointment to the National Aeronautics and Space Administration (NASA) Post-Doctoral Program at the Ames Research Center administered by Universities Space Research Association (USRA) through a contract with NASA. We acknowledge useful exchanges with Mark Gurwell on the ALMA CO observations. This work has made use of data from the European Space Agency (ESA) mission Gaia (https://www.cosmos.esa.int/gaia), processed by the Gaia Data Processing and Analysis Consortium (DPAC, https://www.cosmos.esa.int/web/gaia/dpac/consortium).Funding for the DPAC has been provided by national institutions, in particular the institutions participating in the Gaia Multilateral Agreement. J.L.O., P.S.-S., N.M. and R.D. acknowledge financial support from the State Agency for Research of the Spanish MCIU through the "Center of Excellence Severo Ochoa" award to the Instituto de Astrofisica de Andalucia (SEV-2017-0709), they also acknowledge the financial support by the Spanish grant AYA-2017-84637-R and the Proyecto de Excelencia de la Junta de Andalucia J.A. 2012-FQM1776. The research leading to these results has received funding from the European Union's Horizon 2020 Research and Innovation Programme, under Grant Agreement no. 687378, as part of the project "Small Bodies Near and Far" (SBNAF). P.S.-S. acknowledges financial support by the Spanish grant AYA-RTI2018-098657-J-I00 "LEO-SBNAF". The work was partially based on observations made at the Laboratorio Nacional de Astrofisica (LNA), Itajuba-MG, Brazil. The following authors acknowledge the respective CNPq grants: F.B.-R. 309578/2017-5; R.V.-M. 304544/2017-5, 401903/2016-8; J.I.B.C. 308150/2016-3 and 305917/2019-6; M.A. 427700/20183, 310683/2017-3, 473002/2013-2. This study was financed in part by the Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior -Brasil (CAPES) -Finance Code 001 and the National Institute of Science and Technology of the e-Universe project (INCT do e-Universo, CNPq grant 465376/2014-2). G.B.R. acknowledges CAPES-FAPERJ/PAPDRJ grant E26/203.173/2016 and CAPES-PRINT/UNESP grant 88887.571156/2020-00, M.A. FAPERJ grant E26/111.488/2013 and A.R.G.Jr. FAPESP grant 2018/11239-8. B.E.M. thanks CNPq 150612/2020-6 and CAPES/Cofecub-394/2016-05 grants. Part of the photometric data used in this study were collected in the frame of the photometric observations with the robotic and remotely controlled telescope at the University of Athens Observatory (UOAO; Gazeas 2016). The 2.3 m Aristarchos telescope is operated on Helmos Observatory by the Institute for Astronomy, Astrophysics, Space Applications and Remote Sensing of the National Observatory of Athens. Observations with the 2.3 m Aristarchos telescope were carried out under OPTICON programme. This project has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No 730890. This material reflects only the authors views and the Commission is not liable for any use that may be made of the information contained therein. The 1. 2m Kryoneri telescope is operated by the Institute for Astronomy, Astrophysics, Space Applications and Remote Sensing of the National Observatory of Athens. The Astronomical Observatory of the Autonomous Region of the Aosta Valley (OAVdA) is managed by the Fondazione Clement Fillietroz-ONLUS, which is supported by the Regional Government of the Aosta Valley, the Town Municipality of Nus and the "Unite des Communes valdotaines Mont-Emilius". The 0.81 m Main Telescope at the OAVdA was upgraded thanks to a Shoemaker NEO Grant 2013 from The Planetary Society. D.C. and J.M.C. acknowledge funds from a 2017 'Research and Education' grant from Fondazione CRT-Cassa di Risparmio di Torino. P.M. acknowledges support from the Portuguese Fundacao para a Ciencia e a Tecnologia ref. PTDC/FISAST/29942/2017 through national funds and by FEDER through COMPETE 2020 (ref. POCI010145 FEDER007672). F.J. acknowledges Jean Luc Plouvier for his help. S.J.F. and C.A. would like to thank the UCL student support observers: Helen Dai, Elise Darragh-Ford, Ross Dobson, Max Hipperson, Edward Kerr-Dineen, Isaac Langley, Emese Meder, Roman Gerasimov, Javier Sanjuan, and Manasvee Saraf. We are grateful to the CAHA, OSN and La Hita Observatory staffs. This research is partially based on observations collected at Centro Astronomico HispanoAleman (CAHA) at Calar Alto, operated jointly by Junta de Andalucia and Consejo Superior de Investigaciones Cientificas (IAA-CSIC). This research was also partially based on observation carried out at the Observatorio de Sierra Nevada (OSN) operated by Instituto de Astrofisica de Andalucia (CSIC). This article is also based on observations made with the Liverpool Telescope operated on the island of La Palma by Liverpool John Moores University in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofisica de Canarias with financial support from the UK Science and Technology Facilities Council. Partially based on observations made with the Tx40 and Excalibur telescopes at the Observatorio Astrofisico de Javalambre in Teruel, a Spanish Infraestructura Cientifico-Tecnica Singular (ICTS) owned, managed and operated by the Centro de Estudios de Fisica del Cosmos de Aragon (CEFCA). Tx40 and Excalibur are funded with the Fondos de Inversiones de Teruel (FITE). A.R.R. would like to thank Gustavo Roman for the mechanical adaptation of the camera to the telescope to allow for the observation to be recorded. R.H., J.F.R., S.P.H. and A.S.L. have been supported by the Spanish projects AYA2015-65041P and PID2019-109467GB-100 (MINECO/FEDER, UE) and Grupos Gobierno Vasco IT1366-19. Our great thanks to Omar Hila and their collaborators in Atlas Golf Marrakech Observatory for providing access to the T60cm telescope. TRAPPIST is a project funded by the Belgian Fonds (National) de la Recherche Scientifique (F.R.S.-FNRS) under grant PDR T.0120.21. TRAPPIST-North is a project funded by the University of Liege, and performed in collaboration with Cadi Ayyad University of Marrakesh. E.J. is a FNRS Senior Research Associate., Context. A stellar occultation by Neptune's main satellite, Triton, was observed on 5 October 2017 from Europe, North Africa, and the USA. We derived 90 light curves from this event, 42 of which yielded a central flash detection. Aims. We aimed at constraining Triton's atmospheric structure and the seasonal variations of its atmospheric pressure since the Voyager 2 epoch (1989). We also derived the shape of the lower atmosphere from central flash analysis. Methods. We used Abel inversions and direct ray-tracing code to provide the density, pressure, and temperature profiles in the altitude range similar to 8 km to similar to 190 km, corresponding to pressure levels from 9 mu bar down to a few nanobars. Results. (i) A pressure of 1.18 +/- 0.03 mu bar is found at a reference radius of 1400 km (47 km altitude). (ii) A new analysis of the Voyager 2 radio science occultation shows that this is consistent with an extrapolation of pressure down to the surface pressure obtained in 1989. (iii) A survey of occultations obtained between 1989 and 2017 suggests that an enhancement in surface pressure as reported during the 1990s might be real, but debatable, due to very few high S/N light curves and data accessible for reanalysis. The volatile transport model analysed supports a moderate increase in surface pressure, with a maximum value around 2005-2015 no higher than 23 mu bar. The pressures observed in 1995-1997 and 2017 appear mutually inconsistent with the volatile transport model presented here. (iv) The central flash structure does not show evidence of an atmospheric distortion. We find an upper limit of 0.0011 for the apparent oblateness of the atmosphere near the 8 km altitude., Portuguese Foundation for Science and Technology SFRH/BD/131700/2017, European Social Fund (ESF) SFRH/BD/131700/2017, European Research Council under the European Community's H2020 2014-2021 ERC grant 669416, Spanish Government SEV-2017-0709 AYA-2017-84637-R AYA-RTI2018-098657-J-I00, Junta de Andalucia 2012-FQM1776, European Union's Horizon 2020 Research and Innovation Programme, as part of the project "Small Bodies Near and Far" (SBNAF) 687378, Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPQ), Fundacao de Apoio a Pesquisa do Distrito Federal (FAPDF) 309578/2017-5 304544/2017-5 401903/2016-8 308150/2016-3 305917/2019-6 427700/2018-3 310683/2017-3 473002/2013-2, Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES) 001, Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPQ) 465376/2014-2 CAPES-FAPERJ/PAPDRJ grant E26/203.173/2016 CAPES-PRINT/UNESP grant 88887.571156/2020-00, Fundacao Carlos Chagas Filho de Amparo a Pesquisa do Estado do Rio De Janeiro (FAPERJ) E26/111.488/2013, Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP) 2018/11239-8, Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPQ) 150612/2020-6, European Union's Horizon 2020 research and innovation programme 730890, Regional Government of the Aosta Valley, Town Municipality of Nus, Unite des Communes valdotaines Mont-Emilius, Planetary Society, Fondazione CRT-Cassa di Risparmio di Torino, Portuguese Foundation for Science and Technology PTDC/FISAST/29942/2017, FEDER through COMPETE 2020 POCI010145 FEDER007672, UK Research & Innovation (UKRI), Science & Technology Facilities Council (STFC), Fondos de Inversiones de Teruel (FITE), Spanish Government AYA2015-65041P PID2019-109467GB-100, Grupos Gobierno Vasco IT1366-19, Fonds de la Recherche Scientifique - FNRS PDR T.0120.21, University of Liege, CAPES/Cofecub-394/2016-05
Published: 2022

4. Star-forming early-type galaxies and quiescent late-type galaxies in the local Universe

Author: E.-D. Paspaliaris, E. M. Xilouris, A. Nersesian, S. Bianchi, I. Georgantopoulos, V. A. Masoura, G. E. Magdis, and M. Plionis
Subjects: PHYSICAL-PROPERTIES, interactions [Galaxies], SPECTRAL ENERGY-DISTRIBUTIONS, stellar content, star formation [Galaxies], star formation, ELLIPTIC GALAXIES, ISM [Galaxies], galaxies, evolution, Dust, extinction, ISM, SUBMILLIMETER LUMINOSITY, CLUSTER GALAXIES, extinction, Astronomy and Astrophysics, interactions, evolution [Galaxies], Physics and Astronomy, Space and Planetary Science, MASS ASSEMBLY GAMA, SECULAR EVOLUTION, DIGITAL SKY SURVEY, stellar content [Galaxies], dust, STELLAR MASS, SDSS-IV MANGA
Abstract: Aims. The general consensus is that late-type galaxies undergo intense star-formation, activity while early-type galaxies are mostly inactive. We question this general rule and investigate the existence of star-forming early-type and quiescent late-type galaxies in the local Universe. By computing the physical properties of these galaxies and by using information on their structural properties as well as the density of their local environment, we seek to understand the differences from their ‘typical’ counterparts. Methods. We made use of the multi-wavelength photometric data (from the ultraviolet to the sub-millimetre), for 2209 morphologically classified galaxies in the Galaxy And Mass Assembly survey. Furthermore, we separated the galaxies into subsets of star-forming and quiescent based on their dominant ionising process, making use of established criteria based on the WHα width and the [NII/Hα] ratio. Taking advantage of the spectral energy distribution fitting code CIGALE, we derived galaxy properties, such as the stellar mass, dust mass, and star-formation rate, and we also estimated the unattenuated and the dust-absorbed stellar emission, for both the young (≤200 Myr) and old (> 200 Myr) stellar populations. Results. We find that about 47% of E/S0 galaxies in our sample show ongoing star-formation activity and 8% of late-type galaxies are quiescent. The star-forming elliptical galaxies, together with the little blue spheroids, constitute a population that follows the star-forming main sequence of spiral galaxies very well. The fraction of the luminosity originating from young stars in the star-forming early-type galaxies is quite substantial (∼25%) and similar to that of the star-forming late-type galaxies. The stellar luminosity absorbed by the dust (and used to heat the dust grains) is highest in star-forming E/S0 galaxies (an average of 35%) followed by star-forming Sa-Scd galaxies (27%) with this fraction becoming significantly smaller for their quiescent analogues (6% and 16%, for E/S0 and Sa-Scd, respectively). Star-forming and quiescent E/S0 galaxies donate quite different fractions of their young stellar luminosities to heat up the dust grains (74% and 36%, respectively), while these fractions are very similar for star-forming and quiescent Sa-Scd galaxies (59% and 60%, respectively). Investigating possible differences between star-forming and quiescent galaxies, we find that the intrinsic (unattenuated) shape of the SED of the star-forming galaxies is, on average, very similar for all morphological types. Concerning their structural parameters, quiescent galaxies tend to show larger values of the r-band Sérsic index and larger effective radii (compared to star-forming galaxies). Finally, we find that star-forming galaxies preferably reside in lower density environments compared to the quiescent ones, which exhibit a higher percentage of sources being members of groups.
Published: 2022

5. Erratum: The first maps of κd – the dust mass absorption coefficient – in nearby galaxies, with DustPedia

Author: C J R Clark, P De Vis, M Baes, S Bianchi, V Casasola, L P Cassarà, J I Davies, W Dobbels, S Lianou, I De Looze, R Evans, M Galametz, F Galliano, A P Jones, S C Madden, A V Mosenkov, S Verstocken, S Viaene, E M Xilouris, and N Ysard
Subjects: Space and Planetary Science, Astronomy and Astrophysics
Published: 2022

6. Fraction of bolometric luminosity absorbed by dust in DustPedia galaxies

Author: A. Nersesian, Anthony P. Jones, Wouter Dobbels, Aleksandr V. Mosenkov, I. De Looze, Jonathan Ivor Davies, Simone Bianchi, S. C. Madden, Frédéric Galliano, Maud Galametz, Letizia P. Cassarà, P. De Vis, Viviana Casasola, Sophia Lianou, Maarten Baes, Sébastien Viaene, Christopher J. R. Clark, E. M. Xilouris, Ana Trčka, Istituto di Astrofisica e Planetologia Spaziali - INAF (IAPS), Istituto Nazionale di Astrofisica (INAF), Institut d'astrophysique spatiale (IAS), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Sterrenkundig Observatorium, Universiteit Gent = Ghent University (UGENT), University of Hertfordshire [Hatfield] (UH), National Observatory of Athens (NOA), The Central Astronomical Observatory of the Russian Academy of Sciences [Pulkovo], Russian Academy of Sciences [Moscow] (RAS), INAF - Osservatorio Astronomico di Milano (OAM), Cardiff University, Astrophysique Interprétation Modélisation (AIM (UMR_7158 / UMR_E_9005 / UM_112)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), European Project: 606847,EC:FP7:SPA,FP7-SPACE-2013-1,DUSTPEDIA(2014), Universiteit Gent, Universiteit Gent = Ghent University [Belgium] (UGENT), Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Curtin University [Perth], Planning and Transport Research Centre (PATREC), University of Cambridge [UK] (CAM), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7), Universiteit Gent [Ghent], and Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Centre National d'Études Spatiales [Toulouse] (CNES)
Subjects: Stellar mass, INFRARED-EMISSION, DATA RELEASE, Extinction (astronomy), FOS: Physical sciences, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, galaxies [infrared], 01 natural sciences, Luminosity, [PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], 0103 physical sciences, Galaxy formation and evolution, Astrophysics::Solar and Stellar Astrophysics, EDGE-ON GALAXIES, 010303 astronomy & astrophysics, evolution [galaxies], ComputingMilieux_MISCELLANEOUS, Astrophysics::Galaxy Astrophysics, Cosmic dust, Luminous infrared galaxy, Physics, MASS-SELECTED SAMPLES, ISM [galaxies], SUBMILLIMETER LUMINOSITY, extinction, 010308 nuclear & particles physics, HERSCHEL-ATLAS, Astronomy and Astrophysics, Astrophysics - Astrophysics of Galaxies, Galaxy, EXTRAGALACTIC BACKGROUND LIGHT, SPECTRAL ENERGY-DISTRIBUTION, Physics and Astronomy, 13. Climate action, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), photometry [galaxies], Spectral energy distribution, dust, Astrophysics::Earth and Planetary Astrophysics, SPIRAL GALAXIES, INTERSTELLAR DUST
Abstract: We study the fraction of stellar radiation absorbed by dust, f_abs, in 814 galaxies of different morphological types. The targets constitute the vast majority (93%) of the DustPedia sample, including almost all large (optical diameter larger than 1'), nearby (v, 21 pages, 14 figures, A&A accepted. Template SEDs available at the DustPedia Archive: http://dustpedia.astro.noa.gr/
Published: 2018

7. First optical detection of the supernova remnant G 15.1-1.6

Author: P. Boumis, C. D. Goudis, Fotis Mavromatakis, E. M. Xilouris, J. Alikakos, and P. E. Christopoulou
Subjects: Physics, Astrophysics::High Energy Astrophysical Phenomena, Astrophysics (astro-ph), Doubly ionized oxygen, FOS: Physical sciences, Flux, Astronomy and Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, Electron, Spectral line, Lower limit, Space and Planetary Science, Astrophysics::Solar and Stellar Astrophysics, Emission spectrum, Optical emission spectroscopy, Supernova remnant, Astrophysics::Galaxy Astrophysics
Abstract: Deep optical CCD images of the supernova remnant G 15.1-1.6 were obtained and filamentary and diffuse emission has been discovered. The images, taken in the emission lines of Halpha+[N II], [S II] and [O III], reveal filamentary and diffuse structures all around the remnant. The radio emission at 4850 MHz in the same area is found to be well correlated with the brightest optical filaments. The IRAS 60 micron emission may also be correlated with the optical emission but to a lesser extent. The flux calibrated images suggest that the optical emission originates from shock-heated gas ([S II]/Halpha > 0.4), while there is a possible HII region ([S II]/Halpha ~0.3) contaminating the supernova remnant's emission to the east. Furthermore, deep long-slit spectra were taken at two bright filaments and also show that the emission originates from shock heated gas. An [O III] filamentary structure has also been detected further to the west but it lies outside the remnant's boundaries and possibly is not associated to it. The [O III] flux suggests shock velocities into the interstellar "clouds" ~100 km/s, while the [S II] 6716/6731 ratio indicates electron densities up to ~250 cm^{-3}. Finally, the Halpha emission has been measured to be between 2 to 7 x 10^{-16} erg/s/cm^2/arcsec^2, while the lower limit to the distance is estimated at 2.2 kpc., 12 pages, 6 figures, 3 tables. Accepted for pubication in A&A
Published: 2008

8. The optical properties of the G89.0+4.7 (HB 21) supernova remnant

Author: E. M. Xilouris, P. Boumis, and Fotis Mavromatakis
Subjects: Physics, Interstellar medium, Space and Planetary Science, Ionization, Interstellar cloud, Astronomy and Astrophysics, Light emission, Astrophysics, Supernova remnant, Spectral line, Ion, Line (formation)
Abstract: Flux-calibrated CCD images of HB 21 are presented, along with flux calibrated spectra of moderate resolution. The low ionization images reveal filamentary structures in the east, while the emission in the central to west areas may be either filamentary or patchy. The filaments in the east are correlated very well with the radio emission, but a smaller degree of correlation exists for the patchy emission. An area in the west exhibits strong sulfur emission and is probably associated to the remnant. Uncatalogued $\ion{H}{ii}$ regions are present in the area of the remnant, mainly in the south. We find that an ellipse extending for $116\arcmin\times122\arcmin$ incorporates most of the radio and optical emission. The actual physical extent of the remnant depends on the distance, which is not well determined since it ranges from 0.8 to 1.7 kpc. Deep long-slit spectra were also acquired at a number of locations. The H α emission is generally weak, typically below 15 $\times$ 10 -17 erg s -1 cm -2 arcsec -2 . The H β emission was not always detected, suggesting substantial attenuation of the light through the interstellar medium. The medium ionization line of [$\ion{O}{iii}$]5007 A was not detected indicating low shock velocities into the interstellar clouds whose density is estimated to be a few atoms per cm 3 .
Published: 2006

9. Boxy/peanut 'bulges': comparing the structure of galaxies with the underlying families of periodic orbits

Author: E. M. Xilouris and P. A. Patsis
Subjects: Physics, Bar (music), Astrophysics (astro-ph), Rotational symmetry, Structure (category theory), FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, Disc galaxy, Stability (probability), Galaxy, Planar, Space and Planetary Science, Astrophysics::Galaxy Astrophysics, Simple (philosophy)
Abstract: The vertical profiles of disc galaxies are built by the material trapped around stable periodic orbits, which form their "skeletons". According to this, the knowledge of the stability of the main families of periodic orbits in appropriate 3D models, can predict possible morphologies for edge-on disc galaxies. In a pilot survey we compare the orbital structures which lead to the appearance of "peanuts" and "X"-like features with the edge-on profiles of three disc galaxies (IC 2531, NGC 4013 and UGC 2048). The subtraction from the images of a model representing the axisymmetric component of the galaxies reveals the contribution of the non-axisymmetric terms. We find a direct correspondence between the orbital profiles of 3D bars in models and the observed main morphological features of the residuals. We also apply a simple unsharp masking technique in order to study the sharpest features of the images. Our basic conclusion is that the morphology of the boxy "bulges" of these galaxies can be explained by considering disc material trapped around stable 3D periodic orbits. In most models these building-blocks periodic orbits are bifurcated from the planar central family of a non-axisymmetric component, usually a bar, at low order vertical resonances. In such a case the boxy "bulges" are parts of bars seen edge-on. For the three galaxies we study the families associated with the "peanut" or "X"-shape morphology are most probably bifurcations at the vertical 2/1 or 4/1 resonance., Comment: Accepted for publication in MNRAS
Published: 2006

10. Star Formation Relations and CO Spectral Line Energy Distributions across the J-ladder and Redshift

Author: I. Leonidaki, L. Armus, Howard A. Smith, M. Spaans, Thomas R. Greve, Eduardo González-Alfonso, Andrew I. Harris, Yang Gao, Z-Y. Zhang, P. van der Werf, Aaron S. Evans, Fabian Walter, David A. Naylor, Tanio Díaz-Santos, E. M. Xilouris, Carsten Henkel, Susanne Aalto, J. Fischer, Sylvain Veilleux, Gordon J. Stacey, Rowin Meijerink, Axel Weiss, and Astronomy
Subjects: Physics, Star formation, galaxies: starburst, Astronomy and Astrophysics, Astrophysics, ISM: molecules, Redshift, Galaxy, Spectral line, Luminosity, Supernova, Space and Planetary Science, galaxies: formation, galaxies: evolution, Mass fraction, galaxies: ISM, Line (formation)
Abstract: We present FIR [50-300 μm]–CO luminosity relations (i.e., log L_FIR = α log L’_co + β) for the full CO rotational ladder from J = 1-0 up to J = 13-12 for a sample of 62 local (z ≤ 0.1) (Ultra) Luminous Infrared Galaxies (LIRGs; L_(IR[8-1000 μm]) > 10^(11) L ☉) using data from Herschel SPIRE-FTS and ground-based telescopes. We extend our sample to high redshifts (z > 1) by including 35 submillimeter selected dusty star forming galaxies from the literature with robust CO observations, and sufficiently well-sampled FIR/submillimeter spectral energy distributions (SEDs), so that accurate FIR luminosities can be determined. The addition of luminous starbursts at high redshifts enlarge the range of the FIR–CO luminosity relations toward the high-IR-luminosity end, while also significantly increasing the small amount of mid-J/high-J CO line data (J = 5-4 and higher) that was available prior to Herschel. This new data set (both in terms of IR luminosity and J-ladder) reveals linear FIR–CO luminosity relations (i.e., α 1) for J = 1-0 up to J = 5-4, with a nearly constant normalization (β ~ 2). In the simplest physical scenario, this is expected from the (also) linear FIR–(molecular line) relations recently found for the dense gas tracer lines (HCN and CS), as long as the dense gas mass fraction does not vary strongly within our (merger/starburst)-dominated sample. However, from J = 6-5 and up to the J = 13-12 transition, we find an increasingly sublinear slope and higher normalization constant with increasing J. We argue that these are caused by a warm (~100 K) and dense (>10^4 cm^(–3)) gas component whose thermal state is unlikely to be maintained by star-formation-powered far-UV radiation fields (and thus is no longer directly tied to the star formation rate). We suggest that mechanical heating (e.g., supernova-driven turbulence and shocks), and not cosmic rays, is the more likely source of energy for this component. The global CO spectral line energy distributions, which remain highly excited from J = 6-5 up to J = 13-12, are found to be a generic feature of the (U)LIRGs in our sample, and further support the presence of this gas component.
Published: 2014

11. Molecular gas heating mechanisms, and star formation feedback in merger/s tarbursts: NGC 6240 and Arp 193 as case studies

Author: E. M. Xilouris, Zhi-Yu Zhang, Kate G. Isaak, Frank P. Israel, Thomas R. Greve, Paul van der Werf, Padelis P. Papadopoulos, Axel Weiss, and Yu Gao
Subjects: Luminous infrared galaxy, Physics, Photon, Star formation, media_common.quotation_subject, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, Astrophysics - Astrophysics of Galaxies, Universe, Spectral line, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), Mass fraction, Energy (signal processing), Line (formation), media_common
Abstract: We used the SPIRE/FTS instrument aboard the Herschel Space Observatory (HSO) to obtain the Spectral Line Energy Distributions (SLEDs) of CO from J=4-3 to J=13-12 of Arp 193 and NGC 6240, two classical merger/starbursts selected from our molecular line survey of local Luminous Infrared Galaxies (LIRGs: L_{IR}>=10^{11} L_{sol}). The high-J CO SLEDs are then combined with ground-based low-J CO, {13}CO, HCN, HCO+, CS line data and used to probe the thermal and dynamical states of their large molecular gas reservoirs. We find the two CO SLEDs strongly diverging from J=4-3 onwards, with NGC6240 having a much higher CO line excitation than Arp193, despite their similar low-J CO SLEDs and L_{FIR}/L_{CO,1-0}, L_{HCN}/L_{CO} (J=1-0) ratios (proxies of star formation efficiency and dense gas mass fraction). In Arp193, one of the three most extreme starbursts in the local Universe, the molecular SLEDs indicate a small amount ~(5-15)% of dense gas (n>=10^{4}cm^{-3}) unlike NGC6240 where most of the molecular gas (~(60-70)%) is dense n~(10^4-10^5)cm^{-3}. Strong star-formation feedback can drive this disparity in their dense gas mass fractions, and also induce extreme thermal and dynamical states for the molecular gas.In NGC6240, and to a lesser degree in Arp193, we find large molecular gas masses whose thermal states cannot be maintained by FUV photons from Photon Dominated Regions (PDRs). We argue that this may happen often in metal-rich merger/starbursts, strongly altering the initial conditions of star formation. ALMA can now directly probe these conditions across cosmic epoch, and even probe their deeply dust-enshrouded outcome, the stellar IMF averaged over galactic evolution., 54 pages, 19 figures, accepted for publication in The Astrophysical Journal
Published: 2014
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12. Variation in the dust emissivity index across M 33 with Herschel and Spitzer (HerM 33es)

Author: Francoise Combes, Carsten Henkel, Monica Relaño, Pierre Gratier, Martina C. Wiedner, Markus Röllig, Simon Verley, Fatemeh Tabatabaei, J. Braine, Frank P. Israel, P. van der Werf, C. Kramer, E. M. Xilouris, Médéric Boquien, K. F. Schuster, FORMATION STELLAIRE 2014, Laboratoire d'astrodynamique, d'astrophysique et d'aéronomie de bordeaux (L3AB), Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Observatoire aquitain des sciences de l'univers (OASU), Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Laboratoire d'Astrophysique de Bordeaux [Pessac] (LAB), Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Bordeaux (UB), Instituto de RadioAstronomía Milimétrica (IRAM), Centre National de la Recherche Scientifique (CNRS), Astrophysique Interprétation Modélisation (AIM (UMR_7158 / UMR_E_9005 / UM_112)), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7), Institut für Physik (Institut für Physik), Universität Potsdam, Dpto. Fisica Teorica y del Cosmos, Universidad de Granada (UGR), Dept. fısica Teorica y del Cosmos, Institut de RadioAstronomie Millimétrique (IRAM), Leiden Observatory [Leiden], Universiteit Leiden [Leiden], KOSMA, I. Physikalisches Institut [Köln], Universität zu Köln-Universität zu Köln, Institut de Planétologie et d'Astrophysique de Grenoble (IPAG ), Observatoire des Sciences de l'Univers de Grenoble (OSUG), Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Observatoire aquitain des sciences de l'univers (OASU), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Laboratoire d'Astrophysique de Bordeaux [Pessac] (LAB), Astrophysique Interprétation Modélisation (AIM (UMR7158 / UMR_E_9005 / UM_112)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), University of Potsdam = Universität Potsdam, Universidad de Granada = University of Granada (UGR), Universiteit Leiden, Universität zu Köln = University of Cologne-Universität zu Köln = University of Cologne, Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Astrophysique de Grenoble (LAOG), and Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO), Metallicity, Extinction (astronomy), FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, Power law, 0103 physical sciences, Emissivity, Astrophysics::Solar and Stellar Astrophysics, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, Dwarf galaxy, Physics, 010308 nuclear & particles physics, Star formation, [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], Local Group, Astronomy and Astrophysics, [PHYS.ASTR.SR]Physics [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], Astrophysics - Astrophysics of Galaxies, Galaxy, 13. Climate action, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), Astrophysics::Earth and Planetary Astrophysics, Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract: We study the wavelength dependence of the dust emission as a function of position and environment across the disk of M33 at a linear resolution of 160 pc using Spitzer and Herschel photometric data. Expressing the emissivity of the dust as a power law, the power-law exponent (beta) is estimated from two independent approaches designed to properly treat the degeneracy between beta and the dust temperature. Both beta and the dust temperature are higher in the inner disk than in the outer disk, contrary to reported beta-T anti-correlations found in other sources. In the cold + warm dust model, the warm component and the ionized gas (Halpha) have a very similar distribution across the galaxy, demonstrating that the model separates the components in an appropriate fashion. The flocculent spiral arms and the dust lanes are evident in the map of the cold component. Both cold and warm dust column densities are high in star forming regions and reach their maxima toward the giant star forming complexes NGC604 and NGC595. beta declines from close to 2 in the center to about 1.3 in the outer disk. beta is positively correlated with star formation and with molecular gas column, as traced by Halpha and CO emission. The lower dust emissivity index in the outer parts of M33 is likely related to the reduced metallicity (different grain composition) and possibly different size distribution. It is not due to the decrease in stellar radiation field or temperature in a simple way because the FIR-bright regions in the outer disk also have a low beta. Like most spirals, M33 has a (decreasing) radial gradient in star formation and molecular-to-atomic gas ratio such that the regions bright in Halpha or CO tend to trace the inner disk, making it difficult to distinguish between their effects on the dust., 18 pages, 16 figures, Accepted for Publication in Astronomy & Astrophysics Journal
Published: 2014

13. Spectral Energy Distributions of HII regions in M33 (HerM33es)

Author: M. Relano, S. Verley, I. Perez, C. Kramer, D. Calzetti, E. M. Xilouris, M. Boquien, J. Abreu-Vicente, F. Combes, F. Israel, F. S. Tabatabaei, J. Braine, C. Buchbender, M. Gonzalez, P. Gratier, S. Lord, B. Mookerjea, G. Quintana-Lacaci, P. van der Werf, and 2013
Published: 2013

14. Spectral Energy Distributions of HII regions in M33 (HerM33es)

Author: Monica Relaño, Pierre Gratier, Christof Buchbender, Frank P. Israel, G. Quintana-Lacaci, Isabel Pérez, C. Kramer, P. van der Werf, M. Boquien, Fatemeh Tabatabaei, J. Abreu-Vicente, S. D. Lord, S. Verley, M. Gonzalez, J. Braine, Francoise Combes, D. Calzetti, E. M. Xilouris, Bhaswati Mookerjea, Dpto. Fisica Teorica y del Cosmos, Universidad de Granada (UGR), Dept. fısica Teorica y del Cosmos, Instituto de RadioAstronomía Milimétrica (IRAM), Centre National de la Recherche Scientifique (CNRS), Department of Astronomy, University of Massachusetts System (UMASS), Astrophysique Interprétation Modélisation (AIM (UMR_7158 / UMR_E_9005 / UM_112)), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7), Leiden Observatory [Leiden], Universiteit Leiden [Leiden], FORMATION STELLAIRE 2013, Laboratoire d'astrodynamique, d'astrophysique et d'aéronomie de bordeaux (L3AB), Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Observatoire aquitain des sciences de l'univers (OASU), Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Laboratoire d'Astrophysique de Bordeaux [Pessac] (LAB), Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Bordeaux (UB), Institut de RadioAstronomie Millimétrique (IRAM), Institut de Planétologie et d'Astrophysique de Grenoble (IPAG ), Observatoire des Sciences de l'Univers de Grenoble (OSUG), Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), KOSMA, I. Physikalisches Institut, Universität zu Köln, Laboratoire d'Astrophysique de Grenoble (LAOG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Universidad de Granada = University of Granada (UGR), Astrophysique Interprétation Modélisation (AIM (UMR7158 / UMR_E_9005 / UM_112)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Universiteit Leiden, Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Observatoire aquitain des sciences de l'univers (OASU), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Laboratoire d'Astrophysique de Bordeaux [Pessac] (LAB), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), and Universität zu Köln = University of Cologne
Subjects: Electron density, Cosmology and Nongalactic Astrophysics (astro-ph.CO), 010504 meteorology & atmospheric sciences, Shell (structure), FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, Photometry (optics), 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, Emission spectrum, Surface brightness, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, 0105 earth and related environmental sciences, Physics, [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], Astronomy and Astrophysics, [PHYS.ASTR.SR]Physics [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], Astrophysics - Astrophysics of Galaxies, Wavelength, 13. Climate action, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), Spectral energy distribution, Order of magnitude, Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract: Within the framework of the Herschel M 33 extended survey HerM33es we study the Spectral Energy Distribution (SED) of a set of HII regions in M 33 as a function of the morphology. We present a catalogue of 119 HII regions morphologically classified: 9 filled, 47 mixed, 36 shell, and 27 clear shell HII regions. For each object we extract the photometry at twelve available wavelength bands (from FUV-1516A to IR-250mi) and obtain the SED. We also obtain emission line profiles across the regions to study the location of the stellar, ionised gas, and dust components. We find trends for the SEDs related to the morphology, showing that the star and gas-dust configuration affects the ratios of the emission in different bands. The mixed and filled regions show higher emission at 24mi than the shells and clear shells, which could be due to the proximity of the dust to the stellar clusters in the case of mixed and filled regions. The FIR peak for shells and clear shells seems to be located towards longer wavelengths, indicating that the dust is colder for this type of objects.The logarithmic 100/70mi ratio for filled and mixed regions remains constant over one order of magnitude in Halpha and FUV surface brightness, while the shells and clear shells exhibit a wider range of values of almost two orders of magnitude. We derive dust masses and temperatures fitting the individual SEDs with dust models proposed in the literature. The derived dust mass range is between 10^2-10^4 Msun and the cold dust temperature spans T(cold)~12-27 K. The spherical geometrical model proposed for the Halpha clear shells is confirmed by the emission profile obtained from the observations and is used to infer the electron density within the envelope: the typical electron density is 0.7+-0.3 cm^-3, while filled regions can reach values two to five times higher., Comment: 21 pages, 19 figures. Accepted to A&A
Published: 2013
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15. Gas and dust cooling along the major axis of M 33 (HerM33es). ISO/LWS [C ii] observations

Author: M. Boquien, Pierre Gratier, P. van der Werf, Christof Buchbender, S. Verley, C. Kramer, J. Abreu-Vicente, M. Roellig, E. M. Xilouris, Susanne Aalto, J. Braine, T. Nikola, Monica Relaño, Santiago García-Burillo, Frank P. Israel, Instituto de RadioAstronomía Milimétrica (IRAM), Centre National de la Recherche Scientifique (CNRS), Observatorio Astronomico Nacional [Madrid] (OAN), Instituto Geografico Nacional (IGN), Dpto. Fisica Teorica y del Cosmos, Universidad de Granada (UGR), Astrophysique Interprétation Modélisation (AIM (UMR_7158 / UMR_E_9005 / UM_112)), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7), FORMATION STELLAIRE 2013, Laboratoire d'astrodynamique, d'astrophysique et d'aéronomie de bordeaux (L3AB), Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Observatoire aquitain des sciences de l'univers (OASU), Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Laboratoire d'Astrophysique de Bordeaux [Pessac] (LAB), Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Bordeaux (UB), Institut de RadioAstronomie Millimétrique (IRAM), KOSMA, I. Physikalisches Institut [Köln], Universität zu Köln-Universität zu Köln, Dept. fısica Teorica y del Cosmos, Leiden Observatory [Leiden], Universiteit Leiden [Leiden], Observatorio Astronomico Nacional, Madrid, Universidad de Granada = University of Granada (UGR), Astrophysique Interprétation Modélisation (AIM (UMR7158 / UMR_E_9005 / UM_112)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Observatoire aquitain des sciences de l'univers (OASU), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Laboratoire d'Astrophysique de Bordeaux [Pessac] (LAB), Universität zu Köln = University of Cologne-Universität zu Köln = University of Cologne, and Universiteit Leiden
Subjects: Physics, Spiral galaxy, 010308 nuclear & particles physics, [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], Metallicity, Molecular cloud, Semi-major axis, Local Group, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Radiation, Photoelectric effect, [PHYS.ASTR.SR]Physics [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], 7. Clean energy, 01 natural sciences, Astrophysics - Astrophysics of Galaxies, Galaxy, 13. Climate action, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), 0103 physical sciences, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics
Abstract: We aim to better understand the heating of the gas by observing the prominent gas cooling line [CII] at 158um in the low-metallicity environment of the Local Group spiral galaxy M33 at scales of 280pc. In particular, we aim at describing the variation of the photoelectric heating efficiency with galactic environment. In this unbiased study, we used ISO/LWS [CII] observations along the major axis of M33, in combination with Herschel PACS and SPIRE continuum maps, IRAM 30m CO 2-1 and VLA HI data to study the variation of velocity integrated intensities. The ratio of [CII] emission over the far-infrared continuum is used as a proxy for the heating efficiency, and models of photon-dominated regions are used to study the local physical densities, FUV radiation fields, and average column densities of the molecular clouds. The heating efficiency stays constant at 0.8% in the inner 4.5kpc radius of the galaxy where it starts to increase to reach values of ~3% in the outskirts at about 6kpc radial distance. The rise of efficiency is explained in the framework of PDR models by lowered volume densities and FUV fields, for optical extinctions of only a few magnitudes at constant metallicity. In view of the significant fraction of HI emission stemming from PDRs, and for typical pressures found in the Galactic cold neutral medium (CNM) traced by HI emission, the CNM contributes ~15% to the observed [CII] emission in the inner 2kpc radius of M33. The CNM contribution remains largely undetermined in the south, while positions between 2 and 7.3kpc radial distance in the north of M33 show a contribution of ~40%+-20%., (16 pages, a version with higher resolution figures may be downloaded from http://www.iram.es/IRAMES/hermesWiki/HermesPublications)
Published: 2013

16. The Herschel Virgo Cluster Survey - XII. FIR properties of optically selected Virgo cluster galaxies

Author: S. Alighieri di Serego, George J. Bendo, S. C. Madden, Stefano Zibetti, Catherine Vlahakis, Dominik J. Bomans, Médéric Boquien, Alessandro Boselli, I. De Looze, L. K. Hunt, Joris Verstappen, Laure Ciesla, Maarten Baes, Michael Pohlen, Laura Magrini, Giuseppe Gavazzi, M. S. Clemens, Marco Grossi, Jacopo Fritz, Matthew Smith, Robbie Richard Auld, Simone Bianchi, E. M. Xilouris, Ciro Pappalardo, Edvige Corbelli, Luca Cortese, Jonathan Ivor Davies, AUTRES, Space Telescope European Coordinating Facility (STECF), Space Telescope European Coordinating Facility, European Southern Observatory (ESO), Universiteit Gent = Ghent University (UGENT), Astrophysique Interprétation Modélisation (AIM (UMR7158 / UMR_E_9005 / UM_112)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Biophotonique et Pharmacologie - UMR 7213 (LBP), Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique, Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS), Università degli Studi di Milano-Bicocca = University of Milano-Bicocca (UNIMIB), Centro de Astronomia e Astrofísica da Universidade de Lisboa (CAAUL), Universidade de Lisboa = University of Lisbon (ULISBOA), INAF - Osservatorio Astrofisico di Arcetri (OAA), Istituto Nazionale di Astrofisica (INAF), School of Physics and Astronomy [Cardiff], Cardiff University, Sterrenkundig Observatorium, Universiteit Gent = Ghent University [Belgium] (UGENT), Astrophysique Interprétation Modélisation (AIM (UMR_7158 / UMR_E_9005 / UM_112)), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7), Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA)), Università degli Studi di Milano-Bicocca [Milano] (UNIMIB), Universidade de Lisboa (ULISBOA), Universiteit Gent, Universiteit Gent [Ghent], Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Centre National d'Études Spatiales [Toulouse] (CNES), Universitá degli Studi di Milano-Bicocca, Universitá degli Studi di Milan-Bocca, Auld, R, Bianchi, S, Smith, M, Davies, J, Bendo, G, di Serego Alighieri, S, Cortese, L, Baes, M, Bomans, D, Boquien, M, Boselli, A, Ciesla, L, Clemens, M, Corbelli, E, De Looze, I, Fritz, J, Gavazzi, G, Pappalardo, C, Grossi, M, Hunt, L, Madden, S, Magrini, L, Pohlen, M, Verstappen, J, Vlahakis, C, Xilouris, E, and Zibetti, S
Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO), DWARF GALAXIES, Population, Extinction (astronomy), MU-M, FOS: Physical sciences, Astrophysics, 01 natural sciences, galaxies [infrared], MAGELLANIC CLOUDS, 0103 physical sciences, NEARBY GALAXIES, COLD DUST, education, 010303 astronomy & astrophysics, QB, Dwarf galaxy, clusters of galaxies galaxy Virgo, Physics, Luminous infrared galaxy, education.field_of_study, Spiral galaxy, II. DUST, ISM [galaxies], [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], 010308 nuclear & particles physics, extinction, infrared galaxies, Astronomy, Astronomy and Astrophysics, clusters: individual: Virgo [galaxies], galaxies ISM, Virgo Cluster, Galaxy, GAS MASS-RATIO, Physics and Astronomy, Space and Planetary Science, Elliptical galaxy, photometry [galaxies], dust, extinction, dust, SUBMILLIMETER, galaxies photometry, SCIENCE DEMONSTRATION PHASE, SPIRAL GALAXIES, Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract: The Herschel Virgo Cluster Survey (HeViCS) is the deepest, confusion-limited survey of the Virgo Cluster at far-infrared (FIR) wavelengths. The entire survey at full depth covers $\sim$55 sq. deg. in 5 bands (100-500 \micron), encompassing the areas around the central dominant elliptical galaxies (M87, M86 & M49) and extends as far as the NW cloud, the W cloud and the Southern extension. The survey extends beyond this region with lower sensitivity so that the total area covered is 84 sq. deg. In this paper we describe the data, the data acquisition techniques and present the detection rates of the optically selected Virgo Cluster Catalogue (VCC). We detect 254 (34%) of 750 VCC galaxies found within the survey boundary in at least one band and 171 galaxies are detected in all five bands. For the remainder of the galaxies we have measured strict upper limits for their FIR emission. The population of detected galaxies contains early- as well as late-types although the latter dominate the detection statistics. We have modelled 168 galaxies, showing no evidence of a strong synchrotron component in their FIR spectra, using a single-temperature modified blackbody spectrum with a fixed emissivity index ($\beta = 2$). A study of the $\chi^2$ distribution indicates that this model is not appropriate in all cases, and this is supported by the FIR colours which indicate a spread in $\beta$=1--2. Statistical comparison of the dust mass and temperature distributions from 140 galaxies with $\chi^2_{dof=3} < 7.8$ (95% confidence level) shows that late-types have typically colder, more massive dust reservoirs; the early-type dust masses have a mean of ${\rm log}( / M_{\sun}) = 6.3 \pm 0.3 $, while for late-types ${\rm log}( / M_{\sun}) =7.1 \pm 0.1$... (abridged), Comment: 47 pages, 14 figures, 6 tables, accepted for publication in MNRAS
Published: 2013

17. Millimeter and submillimeter excess emission in M 33 revealed byPlanckand LABOCA

Author: T. Ruiz-Lara, I. Hermelo, Simon Verley, Médéric Boquien, Monica Relaño, M. Albrecht, Ute Lisenfeld, E. M. Xilouris, and C. Kramer
Subjects: Physics, 010308 nuclear & particles physics, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, Astrophysics - Astrophysics of Galaxies, 01 natural sciences, symbols.namesake, Space and Planetary Science, Extinction (optical mineralogy), Astrophysics of Galaxies (astro-ph.GA), 0103 physical sciences, symbols, Astrophysics::Solar and Stellar Astrophysics, Millimeter, Planck, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics
Abstract: Previous studies have shown the existence of an excess of emission at submillimeter (submm) and millimeter (mm) wavelengths in the spectral energy distribution (SED) of many low-metallicity galaxies. The goal of the present study is to model separately the emission from the star forming (SF) component and the emission from the diffuse interstellar medium (ISM) in the nearby spiral galaxy M33. We decomposed the observed SED of M33 into its SF and diffuse components. Mid-infrared (MIR) and far-infrared (FIR) fluxes were extracted from Spitzer and Herschel data. At submm and mm wavelengths, we used ground-based observations from APEX to measure the emission from the SF component and data from the Planck space telescope to estimate the diffuse emission. Both components were separately fitted using radiation transfer models based on standard dust properties and a realistic geometry. Both modeled SEDs were combined to build the global SED of M33. In addition, the radiation field necessary to power the dust emission in our modeling was compared with observations from GALEX, Sloan, and Spitzer. Our modeling is able to reproduce the observations at MIR and FIR wavelengths, but we found a strong excess of emission at submm and mm wavelengths, where the model expectations severely underestimate the LABOCA and Planck fluxes. We also found that the ultraviolet (UV) radiation escaping the galaxy is 70% higher than the model predictions. We determined a gas-to-dust mass ratio Gdust~100, significantly lower than the value expected from the sub-solar metallicity of M33. We discussed different hypotheses to explain the discrepancies found in our study (i.e., excess of emission at submm and mm wavelengths, deficit of UV attenuation, and abnormally low value of Gdust), concluding that different dust properties in M33 is the most plausible explanation., Comment: accepted by A&A, 22 pages
Published: 2016

18. The Herschel Fornax Cluster Survey I: The Bright Galaxy Sample

Author: C. Fuller, Laure Ciesla, I. De Looze, Timothy A. Davis, Jonathan Ivor Davies, Matthew Smith, Dominik J. Bomans, S. C. Madden, Maarten Baes, C. Vlahakis, L. K. Hunt, Paolo Serra, D. A. Garcia-Appadoo, Jacopo Fritz, Thomas M. Hughes, S. di Serego Alighieri, Simone Bianchi, M. S. Clemens, E. M. Xilouris, Joris Verstappen, Alessandro Boselli, Institut Pasteur de Montevideo, Réseau International des Instituts Pasteur (RIIP), Universiteit Gent [Ghent], Laboratoire d'Astrophysique de Marseille (LAM), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Centre National d'Études Spatiales [Toulouse] (CNES), Space Telescope European Coordinating Facility (STECF), Space Telescope European Coordinating Facility, Laboratoire de Biophotonique et Pharmacologie - UMR 7213 (LBP), Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique, Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS), INAF - Osservatorio Astrofisico di Arcetri (OAA), Istituto Nazionale di Astrofisica (INAF), AUTRES, Sterrenkundig Observatorium, Universiteit Gent, Ruhr-Universität Bochum [Bochum], Astrophysique Interprétation Modélisation (AIM (UMR_7158 / UMR_E_9005 / UM_112)), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7), Universiteit Gent = Ghent University (UGENT), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Astrophysique Interprétation Modélisation (AIM (UMR7158 / UMR_E_9005 / UM_112)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Universiteit Gent = Ghent University [Belgium] (UGENT), Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA)), Réseau nanophotonique et optique, and Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)
Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO), Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, REGION, Luminosity, ISM [Galaxies], MOLECULAR GAS CONTENT, 0103 physical sciences, clusters individual: Fornax [Galaxies], Astrophysics::Solar and Stellar Astrophysics, COLD DUST, Fornax Cluster, 010303 astronomy & astrophysics, Galaxy cluster, Astrophysics::Galaxy Astrophysics, QB, Cosmic dust, Luminosity function (astronomy), MASS FUNCTION, Physics, ENVIRONMENT, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], 010308 nuclear & particles physics, Spinning dust, Astronomy, Astronomy and Astrophysics, VIRGO CLUSTER, CATALOG, Virgo Cluster, Galaxy, GALACTIC EMISSION, Physics and Astronomy, SPINNING DUST GRAINS, LUMINOSITY FUNCTION, Space and Planetary Science, Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract: International audience; We present Herschel Space Telescope observations of the nearby Fornax cluster at 100, 160, 250, 350 and 500 mu m with a spatial resolution of 7-36 arcsec (10 arcsec approximate to 1 kpc at d(Fornax) = 17.9Mpc). We define a sample of 11 bright galaxies, selected at 500 mu m, that can be directly compared with our past work on the Virgo cluster. We check and compare our results with previous observations made by IRAS and Planck, finding good agreement. The far-infrared luminosity density is higher, by about a factor of 3, in Fornax compared to Virgo, consistent with the higher number density of galaxies. The 100 mu m (42.5-122.5 mu m) luminosity is two orders of magnitude larger in Fornax than in the local field as measured by IRAS. We calculate stellar (L0.4-2.5) and far-infrared (L100-500) luminosities for each galaxy and use these to estimate a mean optical depth of tau = 0.4 +/- 0.1 - the same value as we previously found for Virgo cluster galaxies. For 10 of the 11 galaxies (NGC 1399 excepted), we fit a modified blackbody curve (beta = 2.0) to our observed flux densities to derive dust masses and temperatures of 10(6.54-8.35) M-circle dot and T = 14.6-24.2 K, respectively, values comparable to those found for Virgo. The derived stars-to-gas(atomic) and gas(atomic)-to-dust ratios vary from 1.1-67.6 to 9.8-436.5, respectively, again broadly consistent with values for Virgo. Fornax is a mass overdensity in stars and dust of about 120 when compared to the local field (30 for Virgo). Fornax and Virgo are both a factor of 6 lower overdensities in gas(atomic) than in stars and dust indicating loss of gas, but not dust and stars, in the cluster environment. We consider in more detail two of the sample galaxies. As the brightest source in either Fornax or Virgo, NGC 1365 is also detected by Planck. The Planck data fit the PACS/SPIRE spectral energy distribution out to 1382 mu m with no evidence of other sources of emission ('spinning dust', free-free, synchrotron). At the opposite end of the scale, NGC 1399 is detected only at 500 mu m with the emission probably arising from the nuclear radio source rather than interstellar dust.
Published: 2012

19. The molecular gas in Luminous Infrared Galaxies II: extreme physical conditions, and their effects on the X_{co} factor

Author: Paul van der Werf, E. M. Xilouris, Kate G. Isaak, Padelis P. Papadopoulos, and Yu Gao
Subjects: Physics, Luminous infrared galaxy, Cosmology and Nongalactic Astrophysics (astro-ph.CO), media_common.quotation_subject, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, Astrophysics - Astrophysics of Galaxies, Galaxy, Spectral line, Universe, Space and Planetary Science, Co factor, Astrophysics of Galaxies (astro-ph.GA), Radiative transfer, Energy (signal processing), Line (formation), media_common, Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract: In this work we conclude the analysis of our CO line survey of Luminous Infrared Galaxies (LIRGs: L_{IR}>=10^{11}L_{sol}) in the local Universe (Paper\,I), by focusing on the influence of their average ISM properties on the total molecular gas mass estimates via the so-called X_{co}=M(H_2)/L_{co,1-0} factor. One-phase radiative transfer models of the global CO Spectral Line Energy Distributions (SLEDs) yield an X_{co} distribution with: \sim(0.6+/-0.2) M_{sol}(K km s^{-1} pc^2)^{-1} over a significant range of average gas densities, temperatures and dynamical states. The latter emerges as the most important parameter in determining X_{co}, with unbound states yielding low values and self-gravitating states the highest ones. Nevertheless in many (U)LIRGs where available higher-J CO lines (J=3--2, 4--3, and/or J=6--5) or HCN line data from the literature allow a separate assessment of the gas mass at high densities (>=10^{4} cm^{-3}) rather than a simple one-phase analysis we find that {\it near-Galactic X_{co} (3-6)\, M_sol\,(K\,km^{-1}\,pc^2)^{-1} values become possible.} We further show that in the highly turbulent molecular gas in ULIRGs a high-density component will be common and can be massive enough for its high X_{co} to dominate the average value for the entire galaxy. ......... ...this may have thus resulted to systematic underestimates of molecular gas mass in ULIRGs., Comment: 77 pages, 6 figures, one Table, accepted for publication at The Astrophysical Journal
Published: 2012

20. Cool and warm dust emission from M33 (HerM33es)

Author: P. van der Werf, Pierre Gratier, S. Anderl, Carsten Henkel, Monica Relaño, C. Kramer, F. F. S. van der Tak, S. D. Lord, G. Quintana-Lacaci, Bhaswati Mookerjea, J. Braine, Frank Bertoldi, M. Boquien, Stavros Akras, Fatemeh Tabatabaei, Frank P. Israel, Gordon J. Stacey, Ron Beck, M. Gonzalez, E. M. Xilouris, Remo P. J. Tilanus, Erik Rosolowsky, Christof Buchbender, Francoise Combes, D. Calzetti, S. Verley, B. S. Koribalski, Astronomy, Astrophysique Interprétation Modélisation (AIM (UMR_7158 / UMR_E_9005 / UM_112)), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7), Department of Astronomy, University of Massachusetts System (UMASS), Instituto de RadioAstronomía Milimétrica (IRAM), Centre National de la Recherche Scientifique (CNRS), Max-Planck-Institut für Radioastronomie (MPIFR), FORMATION STELLAIRE 2012, Laboratoire d'astrodynamique, d'astrophysique et d'aéronomie de bordeaux (L3AB), Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Observatoire aquitain des sciences de l'univers (OASU), Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Laboratoire d'Astrophysique de Bordeaux [Pessac] (LAB), Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Bordeaux (UB), Dept. fısica Teorica y del Cosmos, Universidad de Granada (UGR), Dpto. Fisica Teorica y del Cosmos, Institut für Physik (Institut für Physik), Universität Potsdam, Leiden Observatory [Leiden], Universiteit Leiden [Leiden], Institut de Planétologie et d'Astrophysique de Grenoble (IPAG ), Observatoire des Sciences de l'Univers de Grenoble (OSUG), Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), KOSMA, I. Physikalisches Institut, Universität zu Köln, University of British Columbia (UBC), Astrophysique Interprétation Modélisation (AIM (UMR7158 / UMR_E_9005 / UM_112)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Observatoire aquitain des sciences de l'univers (OASU), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Laboratoire d'Astrophysique de Bordeaux [Pessac] (LAB), Universidad de Granada = University of Granada (UGR), University of Potsdam = Universität Potsdam, Universiteit Leiden, Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Universität zu Köln = University of Cologne, Laboratoire d'Astrophysique de Grenoble (LAOG), and Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)
Subjects: galaxies: spiral, Cosmology and Nongalactic Astrophysics (astro-ph.CO), Infrared, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, EXTENDED SURVEY HERM33ES, 01 natural sciences, Luminosity, STAR-FORMATION, DISK, 0103 physical sciences, Emissivity, SPACE, PHOTOMETRY, Astrophysics::Solar and Stellar Astrophysics, NEARBY GALAXIES, COLD DUST, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, Physics, Spiral galaxy, 010308 nuclear & particles physics, [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], Astronomy and Astrophysics, [PHYS.ASTR.SR]Physics [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], Galaxy, Space observatory, Wavelength, Space and Planetary Science, GAS, Local Group, Astrophysics::Earth and Planetary Astrophysics, SPIRAL GALAXY M33, SUBMILLIMETER, galaxies: ISM, Dust emission, Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract: We study the far-infrared emission from the nearby spiral galaxy M33 in order to investigate the dust physical properties such as the temperature and the luminosity density across the galaxy. Taking advantage of the unique wavelength coverage (100, 160, 250, 350 and 500 micron) of the Herschel Space Observatory and complementing our dataset with Spitzer-IRAC 5.8 and 8 micron and Spitzer-MIPS 24 and 70 micron data, we construct temperature and luminosity density maps by fitting two modified blackbodies of a fixed emissivity index of 1.5. We find that the 'cool' dust grains are heated at temperatures between 11 and 28 K with the lowest temperatures found in the outskirts of the galaxy and the highest ones in the center and in the bright HII regions. The infrared/submillimeter total luminosity (5 - 1000 micron) is estimated to be 1.9x10^9 Lsun. 59% of the total luminosity of the galaxy is produced by the 'cool' dust grains (~15 K) while the rest 41% is produced by 'warm' dust grains (~55 K). The ratio of the cool-to-warm dust luminosity is close to unity (within the computed uncertainties), throughout the galaxy, with the luminosity of the cool dust being slightly enhanced in the center of the galaxy. Decomposing the emission of the dust into two components (one emitted by the diffuse disk of the galaxy and one emitted by the spiral arms) we find that the fraction of the emission in the disk in the mid-infrared (24 micron) is 21%, while it gradually rises up to 57% in the submillimeter (500 micron). We find that the bulk of the luminosity comes from the spiral arm network that produces 70% of the total luminosity of the galaxy with the rest coming from the diffuse dust disk. The 'cool' dust inside the disk is heated at a narrow range of temperatures between 18 and 15 K (going from the center to the outer parts of the galaxy)., Comment: 12 pages, 14 figures, accepted for publication in A&A
Published: 2012
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21. Dust and gas power-spectrum in M33 (HERM33ES)

Author: S. D. Lord, Fatemeh Tabatabaei, S. Verley, Frank P. Israel, Remo P. J. Tilanus, Baerbel Koribalski, P. van der Werf, C. Kramer, E. M. Xilouris, G. Quintana-Lacaci, J. Braine, M. Boquien, Francoise Combes, Frank Bertoldi, Christof Buchbender, D. Calzetti, M. Roellig, G. Stacey, F. F. S. van der Tak, Monica Relaño, Pierre Gratier, Kapteyn Astronomical Institute, Astronomy, Astrophysique Interprétation Modélisation (AIM (UMR_7158 / UMR_E_9005 / UM_112)), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7), Department of Astronomy, University of Massachusetts System (UMASS), Instituto de RadioAstronomía Milimétrica (IRAM), Centre National de la Recherche Scientifique (CNRS), Max-Planck-Institut für Radioastronomie (MPIFR), FORMATION STELLAIRE 2012, Laboratoire d'astrodynamique, d'astrophysique et d'aéronomie de bordeaux (L3AB), Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Observatoire aquitain des sciences de l'univers (OASU), Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Laboratoire d'Astrophysique de Bordeaux [Pessac] (LAB), Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Bordeaux (UB), Leiden Observatory [Leiden], Universiteit Leiden [Leiden], Institut de Planétologie et d'Astrophysique de Grenoble (IPAG ), Observatoire des Sciences de l'Univers de Grenoble (OSUG), Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Dpto. Fisica Teorica y del Cosmos, Universidad de Granada (UGR), KOSMA, I. Physikalisches Institut [Köln], Universität zu Köln-Universität zu Köln, Dept. fısica Teorica y del Cosmos, Astrophysique Interprétation Modélisation (AIM (UMR7158 / UMR_E_9005 / UM_112)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Observatoire aquitain des sciences de l'univers (OASU), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Laboratoire d'Astrophysique de Bordeaux [Pessac] (LAB), Universiteit Leiden, Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Universidad de Granada = University of Granada (UGR), Universität zu Köln = University of Cologne-Universität zu Köln = University of Cologne, Laboratoire d'Astrophysique de Grenoble (LAOG), and Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)
Subjects: galaxies: spiral, Cosmology and Nongalactic Astrophysics (astro-ph.CO), FOS: Physical sciences, FLOCCULANT SPIRAL STRUCTURE, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, EXTENDED SURVEY HERM33ES, 01 natural sciences, Spectral line, STAR-FORMATION, DIFFUSE IONIZED-GAS, Bulge, 0103 physical sciences, DARK-MATTER, SMALL-MAGELLANIC-CLOUD, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, Physics, 010308 nuclear & particles physics, Star formation, [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], Spectral density, Astronomy and Astrophysics, Cosmology and Extragalactic Astrophysics, [PHYS.ASTR.SR]Physics [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], galaxies: general, Galaxy, galaxies: individual: M 33, NGC 891, GALACTIC NEUTRAL HYDROGEN, Interstellar medium, Wavelength, Supernova, Space and Planetary Science, Local Group, MOLECULAR CLOUDS, galaxies: structure, galaxies: ISM, Astrophysics - Cosmology and Nongalactic Astrophysics, H-I
Abstract: Power spectra of de-projected images of late-type galaxies in gas and/or dust emission are very useful diagnostics of the dynamics and stability of their interstellar medium. Previous studies have shown that the power spectra can be approximated as two power-laws, a shallow one at large scales (larger than 500 pc) and a steeper one at small scales, with the break between the two corresponding to the line-of-sight thickness of the galaxy disk. We present a thorough analysis of the power spectra of the dust and gas emission at several wavelengths in the nearby galaxy M33. In particular, we use the recently obtained images at five wavelengths by PACS and SPIRE onboard Herschel. The large dynamical range (2-3 dex in scale) of most images allow us to determine clearly the change in slopes from -1.5 to -4, with some variations with wavelength. The break scale is increasing with wavelength, from 100 pc at 24 and 100micron to 350 pc at 500micron, suggesting that the cool dust lies in a thicker disk than the warm dust, may be due to star formation more confined to the plane. The slope at small scale tends to be steeper at longer wavelength, meaning that the warmer dust is more concentrated in clumps. Numerical simulations of an isolated late-type galaxy, rich in gas and with no bulge, like M33, are carried out, in order to better interpret these observed results. Varying the star formation and feedback parameters, it is possible to obtain a range of power-spectra, with two power-law slopes and breaks, which nicely bracket the data. The small-scale power-law is indeed reflecting the 3D behaviour of the gas layer, steepening strongly while the feedback smoothes the structures, by increasing the gas turbulence. M33 appears to correspond to a fiducial model with an SFR of $\sim$ 0.7 Mo/yr, with 10% supernovae energy coupled to the gas kinematics., Comment: 11 pages, 24 figures, accepted in Astronomy & Astrophysics
Published: 2012

22. Dust in Cluster Dwarf Elliptical Galaxies

Author: Dominik J. Bomans, Alessandro Boselli, I. De Looze, George J. Bendo, Dario Fadda, S. Sabatini, Anthony P. Jones, Jacopo Fritz, Jonathan Ivor Davies, C. Giovanardi, S. di Serego Alighieri, Matthew Smith, Edvige Corbelli, Thomas M. Hughes, Luca Cortese, S. C. Madden, Michael Pohlen, E. M. Xilouris, L. K. Hunt, D. A. Garcia-Appadoo, Giuseppe Gavazzi, Marco Grossi, Simone Bianchi, Stefano Zibetti, Joris Verstappen, A. Dariush, D. Pierini, Laura Magrini, Catherine Vlahakis, Maarten Baes, and M. S. Clemens
Subjects: Physics, Elliptical galaxy, Cluster (physics), Astronomy, Astrophysics, Virgo Cluster, Galaxy, Dust lane, Cosmic dust, Dust emission, Dwarf galaxy
Abstract: Based on single cross-scan data of the Herschel Virgo Cluster Survey, we report the first detections of dust in cluster early-type dwarf galaxies: VCC 209, VCC 781 and VCC 951. All three galaxies have dust masses M d ≈ 105 − 106 M⊙ and average dust temperatures ≈ 16–20 K. Since these three early-type dwarfs reside in densely crowded regions close to the center of the Virgo cluster, and several Hi-detected dwarfs in the outskirts of Virgo were not detected by Herschel(implying a dust content < 104 M⊙), this might imply that dust in dwarfs is more closely related to the molecular gas, which is more centrally peaked in a galaxy’s potential well and therefore, not easily removed by any stripping mechanism. We conclude that the removal of interstellar dust from these early-type dwarfs appears to be less efficient than the removal of the Hi gas.
Published: 2011

23. Dust Content of Virgo Star-Forming Dwarf Galaxies

Author: L. K. Hunt, E. M. Xilouris, Giuseppe Gavazzi, Edvige Corbelli, Luca Cortese, A. Boselli, C. Giovanardi, Michael Pohlen, S. di Serego Alighieri, D. Pierini, M. Baes, Matthew Smith, Anthony P. Jones, Marco Grossi, Stefano Zibetti, Jonathan Ivor Davies, Simone Bianchi, Dominik J. Bomans, I. De Looze, Thomas M. Hughes, S. C. Madden, Dario Fadda, D. A. Garcia-Appadoo, A. Dariush, J. Fritz, J. Verstappen, Catherine Vlahakis, George J. Bendo, S. Sabatini, and M. S. Clemens
Subjects: Physics, Star formation, Astrophysics::High Energy Astrophysical Phenomena, Star (game theory), Astronomy, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, Virgo Cluster, Galaxy, Luminosity, Content (measure theory), Astrophysics::Solar and Stellar Astrophysics, Spectral energy distribution, Astrophysics::Earth and Planetary Astrophysics, Astrophysics::Galaxy Astrophysics, Dwarf galaxy
Abstract: We investigate the dust properties of a small sample of Virgo cluster dwarf galaxies drawn from the science demonstration phase data set of the Herschel Virgo Cluster Survey (HeViCS). These galaxies have low metallicities (\(7.8\
Published: 2011

24. Spectral Energy Distributions of a set of H ii regions in M33 (HerM33es)

Author: HerM es Team, Carsten Henkel, J. Braine, Médéric Boquien, Monica Relaño, E. M. Xilouris, C. Kramer, D. Calzetti, Isabel Pérez, S. Verley, KOSMA, I. Physikalisches Institut, Universität zu Köln, Observatoire Astronomique de Marseille Provence (OAMP), Université de Provence - Aix-Marseille 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), FORMATION STELLAIRE 2012, Laboratoire d'astrodynamique, d'astrophysique et d'aéronomie de bordeaux (L3AB), Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Observatoire aquitain des sciences de l'univers (OASU), Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Laboratoire d'Astrophysique de Bordeaux [Pessac] (LAB), Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Bordeaux (UB), Dpto. Fisica Teorica y del Cosmos, Universidad de Granada (UGR), Dept. fısica Teorica y del Cosmos, Instituto de RadioAstronomía Milimétrica (IRAM), Centre National de la Recherche Scientifique (CNRS), Astrophysique Interprétation Modélisation (AIM (UMR_7158 / UMR_E_9005 / UM_112)), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7), Department of Astronomy, University of Massachusetts System (UMASS), FORMATION STELLAIRE 2011, Institut für Physik (Institut für Physik), Universität Potsdam, Universidad de Granada = University of Granada (UGR), Astrophysique Interprétation Modélisation (AIM (UMR7158 / UMR_E_9005 / UM_112)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Observatoire aquitain des sciences de l'univers (OASU), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Laboratoire d'Astrophysique de Bordeaux [Pessac] (LAB), University of Potsdam = Universität Potsdam, and Universität zu Köln = University of Cologne
Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO), 010504 meteorology & atmospheric sciences, Astrophysics::High Energy Astrophysical Phenomena, Shell (structure), FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, Set (abstract data type), ISM: evolution, 0103 physical sciences, Cluster (physics), Astrophysics::Solar and Stellar Astrophysics, 10. No inequality, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, 0105 earth and related environmental sciences, (ISM:) dust, Physics, (ISM:) H ii regions, [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], Morphological type, Spectral density, Local Group, galaxies: M33, Astronomy and Astrophysics, [PHYS.ASTR.SR]Physics [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], Galaxy, Space and Planetary Science, Spectral energy distribution, Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract: Within the framework of the HerM33es Key Project for Herschel and in combination with multi-wavelength data, we study the Spectral Energy Distribution (SED) of a set of HII regions in the Local Group Galaxy M33. Using the Halpha emission, we perform a classification of a selected HII region sample in terms of morphology, separating the objects in filled, mixed, shell and clear shell objects. We obtain the SED for each HII region as well as a representative SED for each class of objects. We also study the emission distribution of each band within the regions. We find different trends in the SEDs for each morphological type that are related to properties of the dust and their associated stellar cluster. The emission distribution of each band within the region is different for each morphological type of object., 3pages, 4 figures. To appear in 'The Spectral Energy Distribution of Galaxies' Proceedings IAU Symposium No 284, 2011
Published: 2011

25. 100 μm and 160 μm emission as resolved star-formation rate estimators in M 33 (HERM33ES)

Author: E. M. Xilouris, F. F. S. van der Tak, B. S. Koribalski, Fatemeh Tabatabaei, J. Braine, Frank P. Israel, S. Verley, Francoise Combes, Markus Röllig, D. Calzetti, P. van der Werf, M. Boquien, C. Kramer, G. Quintana-Lacaci, Monica Relaño, Remo P. J. Tilanus, S. D. Lord, Gordon J. Stacey, Christof Buchbender, Frank Bertoldi, Astrophysique Interprétation Modélisation (AIM (UMR7158 / UMR_E_9005 / UM_112)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Department of Astronomy, University of Massachusetts System (UMASS), Instituto de RadioAstronomía Milimétrica (IRAM), Centre National de la Recherche Scientifique (CNRS), Max-Planck-Institut für Radioastronomie (MPIFR), Observatoire aquitain des sciences de l'univers (OASU), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Astrophysique de Bordeaux [Pessac] (LAB), Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Université Sciences et Technologies - Bordeaux 1 (UB), Laboratoire d'astrodynamique, d'astrophysique et d'aéronomie de bordeaux (L3AB), Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Centre National de la Recherche Scientifique (CNRS), Leiden Observatory [Leiden], Universiteit Leiden, Australia Telescope National Facility, Australian National University (ANU), Dpto. Fisica Teorica y del Cosmos, Universidad de Granada = University of Granada (UGR), Dept. fısica Teorica y del Cosmos, Astronomy, Astrophysique Interprétation Modélisation (AIM (UMR_7158 / UMR_E_9005 / UM_112)), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7), Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Université Sciences et Technologies - Bordeaux 1, École normale supérieure - Paris (ENS Paris)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université de Cergy Pontoise (UCP), Universiteit Leiden [Leiden], Universidad de Granada (UGR), and École normale supérieure - Paris (ENS Paris)
Subjects: galaxies: spiral, Cosmology and Nongalactic Astrophysics (astro-ph.CO), Infrared, ULTRAVIOLET, FOS: Physical sciences, Scale (descriptive set theory), DUST, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, Luminosity, infrared: galaxies, 0103 physical sciences, PHOTOMETRY, Astrophysics::Solar and Stellar Astrophysics, TOTAL INFRARED LUMINOSITY, NEARBY GALAXIES, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, Physics, CALIBRATION, FORMING GALAXIES, 010308 nuclear & particles physics, Star formation, [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], Estimator, Sigma, Astronomy and Astrophysics, galaxies: individual: M33, Cosmology and Extragalactic Astrophysics, [PHYS.ASTR.SR]Physics [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], Astrophysics - Astrophysics of Galaxies, Galaxy, SPITZER, EXTINCTION, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), galaxies: star formation, Astrophysics::Earth and Planetary Astrophysics, FORMATION RATE INDICATORS, Astrophysics - Cosmology and Nongalactic Astrophysics, Galaxy Astrophysics
Abstract: Over the past few years several studies have provided estimates of the SFR (star-formation rate) or the total infrared luminosity from just one infrared band. However these relations are generally derived for entire galaxies, which are known to contain a large scale diffuse emission that is not necessarily related to the latest star-formation episode. We provide new relations to estimate the SFR from resolved star-forming regions at 100 mum and 160 mum. We select individual star-forming regions in the nearby (840 kpc) galaxy M33. We estimate the SFR combining the emission in Halpha and at 24 mum to calibrate the emission at 100 mum and 160 mum as SFR estimators, as mapped with PACS/Herschel. The data are obtained in the framework of the HERM33ES open time key project. There is less emission in the HII regions at 160 mum than at 100 mum. Over a dynamic range of almost 2 dex in Sigma(SFR) we find that the 100 mum emission is a nearly linear estimator of the SFR, whereas that at 160 mum is slightly superlinear. The behaviour of individual star-forming regions is surprisingly similar to that of entire galaxies. At high Sigma(SFR), star formation drives the dust temperature, whereas uncertainties and variations in radiation-transfer and dust-heated processes dominate at low Sigma(SFR). Detailed modelling of both galaxies and individual star forming regions will be needed to interpret similarities and differences between the two and assess the fraction of diffuse emission in galaxies., 5 pages, 3 figures, accepted for publication in the A&A Herschel special issue
Published: 2010

26. PACS and SPIRE photometer maps of M33: First results of the Herschel M33 extended survey (HERM33ES)

Author: C. Kramer, C. Buchbender, E. M. Xilouris, M. Boquien, J. Braine, D. Calzetti, S. Lord, B. Mookerjea, G. Quintana-Lacaci, M. Relaño, G. Stacey, F. S. Tabatabaei, S. Verley, S. Aalto, S. Akras, M. Albrecht, S. Anderl, R. Beck, F. Bertoldi, F. Combes, M. Dumke, S. Garcia-Burillo, M. Gonzalez, P. Gratier, R. Güsten, C. Henkel, F. P. Israel, B. Koribalski, A. Lundgren, J. Martin-Pintado, M. Röllig, E. Rosolowsky, K. F. Schuster, K. Sheth, A. Sievers, J. Stutzki, R. P. J. Tilanus, F. van der Tak, P. van der Werf, M. C. Wiedner, Instituto de RadioAstronomía Milimétrica (IRAM), Centre National de la Recherche Scientifique (CNRS), Astrophysique Interprétation Modélisation (AIM (UMR7158 / UMR_E_9005 / UM_112)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Department of Astronomy, University of Massachusetts System (UMASS), Observatoire aquitain des sciences de l'univers (OASU), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Astrophysique de Bordeaux [Pessac] (LAB), Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Université Sciences et Technologies - Bordeaux 1 (UB), Laboratoire d'astrodynamique, d'astrophysique et d'aéronomie de bordeaux (L3AB), KOSMA, I. Physikalisches Institut, Universität zu Köln = University of Cologne, Dpto. Fisica Teorica y del Cosmos, Universidad de Granada = University of Granada (UGR), Dept. fısica Teorica y del Cosmos, Institute of Physics, Berlin, HUMBOLT UNIV., Max-Planck-Institut für Radioastronomie (MPIFR), Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Centre National de la Recherche Scientifique (CNRS), Observatorio Astronomico Nacional, Madrid, Fundación Venezolana de Investigaciones Sismológicas (FUNVISIS), FUNVISIS, Instituto de Ciencias de la Tierra, Universidad Central de Venezuela (UCV), Institut für Physik (Institut für Physik), University of Potsdam = Universität Potsdam, Australia Telescope National Facility, Australian National University (ANU), KOSMA, I. Physikalisches Institut [Köln], Universität zu Köln = University of Cologne-Universität zu Köln = University of Cologne, University of British Columbia (UBC), Institut de RadioAstronomie Millimétrique (IRAM), Spitzer Science Center, California Institute of Technology, Pasadena, California Institute of Technology (CALTECH), Astronomy, Astrophysique Interprétation Modélisation (AIM (UMR_7158 / UMR_E_9005 / UM_112)), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7), Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Université Sciences et Technologies - Bordeaux 1, Universität zu Köln, Universidad de Granada (UGR), École normale supérieure - Paris (ENS Paris), Observatorio Astronomico Nacional [Madrid] (OAN), Instituto Geografico Nacional (IGN), Universität Potsdam, Universität zu Köln-Universität zu Köln, École normale supérieure - Paris (ENS Paris)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université de Cergy Pontoise (UCP), and UNIVERSIDAD CENTRAL DE VENEZUELA
Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO), 010504 meteorology & atmospheric sciences, Metallicity, FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, GALAXY M33, STAR-FORMATION, NEARBY, 0103 physical sciences, Emissivity, Astrophysics::Solar and Stellar Astrophysics, COLD DUST, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, 0105 earth and related environmental sciences, Physics, Spiral galaxy, extinction, [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], Astronomy and Astrophysics, Radius, galaxies: individual: M33, Cosmology and Extragalactic Astrophysics, [PHYS.ASTR.SR]Physics [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], Galaxy, CLOUD, Interstellar medium, INFRARED STRUCTURE, Wavelength, Spire, Space and Planetary Science, Local Group, MILKY-WAY, dust, dust, extinction, Astrophysics::Earth and Planetary Astrophysics, galaxies: evolution, EMISSION, galaxies: ISM, Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract: Within the framework of the HERM33ES key project, we are studying the star forming interstellar medium in the nearby, metal-poor spiral galaxy M33, exploiting the high resolution and sensitivity of Herschel. We use PACS and SPIRE maps at 100, 160, 250, 350, and 500 micron wavelength, to study the variation of the spectral energy distributions (SEDs) with galacto-centric distance. Detailed SED modeling is performed using azimuthally averaged fluxes in elliptical rings of 2 kpc width, out to 8 kpc galacto-centric distance. Simple isothermal and two-component grey body models, with fixed dust emissivity index, are fitted to the SEDs between 24 and 500 micron using also MIPS/Spitzer data, to derive first estimates of the dust physical conditions. The far-infrared and submillimeter maps reveal the branched, knotted spiral structure of M33. An underlying diffuse disk is seen in all SPIRE maps (250-500 micron). Two component fits to the SEDs agree better than isothermal models with the observed, total and radially averaged flux densities. The two component model, with beta fixed at 1.5, best fits the global and the radial SEDs. The cold dust component clearly dominates; the relative mass of the warm component is less than 0.3% for all the fits. The temperature of the warm component is not well constrained and is found to be about 60K plus/minus 10K. The temperature of the cold component drops significantly from about 24K in the inner 2 kpc radius to 13K beyond 6 kpc radial distance, for the best fitting model. The gas-to-dust ratio for beta=1.5, averaged over the galaxy, is higher than the solar value by a factor of 1.5 and is roughly in agreement with the subsolar metallicity of M33., Comment: 5 pages, 3 figures, accepted for publication in the A&A Herschel Special Issue
Published: 2010
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27. Black hole accretion and star formation as drivers of gas excitation and chemistry in Markarian 231

Author: Axel Weiss, Fabian Walter, Marco Spaans, C. Kramer, S. D. Lord, Andrew I. Harris, Kalliopi Dasyra, V. Charmandaris, Thomas R. Greve, K. G. Isaak, Eduardo González-Alfonso, C. Vlahakis, Rolf Guesten, Howard A. Smith, Philippos Papadopoulos, L. Armus, A. Rykala, Frank P. Israel, Joseph M. Mazzarella, Yang Gao, Jesús Martín-Pintado, David A. Naylor, A. F. Loenen, Carsten Henkel, Aaron S. Evans, Rowin Meijerink, Luigi Spinoglio, P. van der Werf, Gordon J. Stacey, Susanne Aalto, E. M. Xilouris, Trevor Fulton, Sylvain Veilleux, Martina C. Wiedner, J. Fischer, D. B. Sanders, Giorgio Savini, Leiden Observatory, Cardiff University, Kapteyn Astronomical Institute, University of Groningen, Blue Sky Spectroscopy (BSS), Max-Planck-Institut für Astronomie (MPIA), Max-Planck-Institut für Radioastronomie (MPIfR), Spitzer Science Center, California Institute of Technology (SSC), Remote Sensing Division, Naval Research laboratory, Naval Research Laboratory (NRL), Department of Astronomy, University of Maryland, University College of London [London] (UCL), Infrared Processing Analysis Center, California Institute of Technology (IPAC), Harvard-Smithsonian Center for Astrophysics, Departamente de Física, Universidad de Alcalá Henares, Department of Physics, University of Lethbridge, Department of Radio and Space Science, Chalmers University of Technology, Crete Center for Theoretical Physics, Department of Physics, Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Astronomy Department, University of Virginia, Charlottesville, Purple Mountain Observatory, Instituto de Radio Astronomía Milimétrica (IRAM), Departamento de Astrofisica Molecular e Infrarroja-Instituto de Estructura de la Materia, Consejo Superior de Investigaciones Científica (CSIC), Rheinische Friedrich-Wilhelms-Universität Bonn, Institute for Astronomy, University of Hawaii, Istituto di Fisica dello Spazio Interplanetario (IFSI), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), Department of Astronomy, Cornell University, Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Centre National de la Recherche Scientifique (CNRS), Institute of Astronomy and Astrophysics, National Observatory of Athens, and Astronomy
Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO), GALAXY NUCLEI, Infrared, Astrophysics::High Energy Astrophysical Phenomena, galaxies: active, FOS: Physical sciences, galaxies: starburst, LINES, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Radiation, DIAGNOSTICS, galaxies: individual: Mrk 231, infrared: galaxies, DENSE GAS, Astrophysics::Galaxy Astrophysics, Physics, Supermassive black hole, Star formation, Radiation field, Astronomy and Astrophysics, Astrophysics - Astrophysics of Galaxies, Accretion (astrophysics), Galaxy, CO, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), Astrophysics::Earth and Planetary Astrophysics, galaxies: nuclei, EMISSION, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Excitation, galaxies: ISM, Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract: We present a full high resolution SPIRE FTS spectrum of the nearby ultraluminous infrared galaxy Mrk231. In total 25 lines are detected, including CO J=5-4 through J=13-12, 7 rotational lines of H2O, 3 of OH+ and one line each of H2O+, CH+, and HF. We find that the excitation of the CO rotational levels up to J=8 can be accounted for by UV radiation from star formation. However, the approximately flat luminosity distribution of the CO lines over the rotational ladder above J=8 requires the presence of a separate source of excitation for the highest CO lines. We explore X-ray heating by the accreting supermassive black hole in Mrk231 as a source of excitation for these lines, and find that it can reproduce the observed luminosities. We also consider a model with dense gas in a strong UV radiation field to produce the highest CO lines, but find that this model strongly overpredicts the hot dust mass in Mrk231. Our favoured model consists of a star forming disk of radius 560 pc, containing clumps of dense gas exposed to strong UV radiation, dominating the emission of CO lines up to J=8. X-rays from the accreting supermassive black hole in Mrk231 dominate the excitation and chemistry of the inner disk out to a radius of 160 pc, consistent with the X-ray power of the AGN in Mrk231. The extraordinary luminosity of the OH+ and H2O+ lines reveals the signature of X-ray driven excitation and chemistry in this region., 5 pages, 2 figures, accepted for publication in Astronomy & Astrophysics Special Issue on Herschel first results
Published: 2010

28. Multi band optical micro variability of BL Lac objects

Author: I. E. Papadakis, E. P. Christopoulou, P. Boumis, and E. M. Xilouris
Subjects: Physics, Multi band, Astrophysics, BL Lac object
Published: 2009

29. The X-ray variability and the near-IR to X-ray spectral energy distribution of four low luminosity Seyfert 1 galaxies

Author: E. M. Xilouris, W. Brinkmann, I. E. Papadakis, and Z. Ioannou
Subjects: Physics, Spectral shape analysis, Astrophysics::High Energy Astrophysical Phenomena, Astrophysics (astro-ph), FOS: Physical sciences, Astronomy and Astrophysics, Quasar, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Galaxy, Accretion (astrophysics), Spectral line, Amplitude, Space and Planetary Science, Radiative transfer, Spectral energy distribution, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Galaxy Astrophysics
Abstract: We present the results from a study of the X-ray variability and the near-IR to X-ray spectral energy distribution of four low-luminosity, Seyfert 1 galaxies. We compared their variability amplitude and broad band spectrum with those of more luminous AGN in order to investigate whether accretion in low-luminosity AGN operates as in their luminous counterparts. We used archival XMM-Newton and, in two cases, ASCA data to estimate their X-ray variability amplitude and determine their X-ray spectral shape and luminosity. We also used archival HST data to measure their optical nuclear luminosity, and near-IR measurements from the literature, in order to construct their near-IR to X-ray spectra. The X-ray variability amplitude of the four Seyferts is what one would expect, given their black hole masses. Their near-IR to X-ray spectrum has the same shape as the spectrum of quasars which are 10^2-10^5 times more luminous. The objects in our sample are optically classified as Seyfert 1-1.5. This implies that they host a relatively unobscured AGN-like nucleus. They are also of low luminosity and accrete at a low rate. They are therefore good candidates to detect radiation from an inefficient accretion process. However, our results suggest that they are similar to AGN which are 10^2-10^5 times more luminous. The combination of a "radiative efficient accretion disc plus an X-ray producing hot corona" may persist at low accretion rates as well., Comment: 11 pages, 8 figures, accepted for publication in A&A
Published: 2008
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30. New Planetary Nebulae in the Galactic Bulge region with l>0deg - II

Author: P. Boumis, E. Kapakos, C. D. Goudis, Fotis Mavromatakis, J. Papamastorakis, Stavros Akras, and E. M. Xilouris
Subjects: Physics, Spectral signature, Low resolution, Astrophysics::High Energy Astrophysical Phenomena, Doubly ionized oxygen, Astronomy and Astrophysics, Electron, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Planetary nebula, Spectral line, Space and Planetary Science, Bulge, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Galaxy Astrophysics, Line (formation)
Abstract: The presentation of new results from an [O III] 5007 A survey in a search for planetary nebulae (PNe) in the galactic bulge is continued. A total of 60 objects, including 19 new PNe, have been detected in the remaining 34 per cent of the survey area, while 41 objects are already known. Deep Halpha+[N II] CCD images as well as low resolution spectra have been acquired for these objects. Their spectral signatures suggest that the detected emission originates from photoionized nebulae. In addition, absolute line fluxes have been measured and the electron densities are given. Accurate optical positions and optical diameters are also determined., Comment: 14 pages, 5 figures, accepted for publication in MNRAS
Published: 2006

31. Dust along a merging galaxy sequence

Author: E. M. Xilouris, A. Misiriotis, Antonis Georgakakis, and Vassilis Charmandaris
Subjects: Physics, Star formation, Astronomy, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, Galaxy merger, Dust lane, Galaxy, Stars, Circumstellar dust, Astrophysics::Earth and Planetary Astrophysics, Infrared cirrus, Astrophysics::Galaxy Astrophysics, Cosmic dust
Abstract: We investigate the cold and warm dust properties during galaxy interactions using a merging galaxy sample ordered into a chronological sequence from pre‐ to post‐mergers. Our sample comprises a total of 29 merging systems selected to have far‐infrared and sub‐millimeter observations. We use the 100‐to‐850μm flux density ratio, f100/f850, as a proxy to the mass fraction of the warm and the cold dust in these systems. We find evidence for an increase in f100/f850 along the merging sequence from early to advanced mergers and interpret this trend as an increase of the warm relative to the cold dust mass. We argue that the two key parameters affecting the f100/f850 flux ratio is the star‐formation rate and the dust content of individual systems relative to the stars. Using a sophisticated model for the absorption and re‐emission of the stellar UV radiation by dust we show that these parameters can indeed explain both the increase and the observed scatter in the f100/f850 along the merging galaxy sequence.
Published: 2006

32. The distribution of the ISM in the Milky Way

Author: A. Misiriotis and E. M. Xilouris
Subjects: Physics, Spiral galaxy, Milky Way, Extinction (astronomy), Megamaser, Astronomy, Astrophysics::Cosmology and Extragalactic Astrophysics, Star count, Astrophysics, Galaxy, Thin disk, Astrophysics::Earth and Planetary Astrophysics, Astrophysics::Galaxy Astrophysics, Oort constants
Abstract: We use the COBE/DIRBE (1.2, 2.2, 60, 100, 140 and 240 μm) maps and the COBE/FIRAS spectra (for the wavelength range 100 – 1000 μm) to constrain a model for the spatial distribution of the dust, the stars and the gas in the Milky Way. By assumming exponential axisymmetric distributions for the dust and the stars and by performing the corresponding radiative transfer calculations we reproduce the FIR and NIR maps of the Milky Way. Similar distributions for the atomic and molecular hydrogen in the disk are used (with an inner cut off radius for the atomic Hydrogen) to fit the gas data. The star formation rate surface density is ploted against the gas surface density and an “intrinsic” Galactic Schmidt law is derived with excellent agreement with the “external” Schmidt law found for spiral galaxies. The Milky Way is found to consume ∼ 1% and ∼ 10% of its gas in the outer and inner regions respectively (for a period of 0.1 Gyr) for making stars. The dust‐induced B‐V colour excess observed in various directions...
Published: 2006

33. ARISTARCHOS: The New 2.3 m Greek Telescope

Author: C. D. Goudis, P. Boumis, E. M. Xilouris, and P. Hantzios
Subjects: Physics, Telescope, Spectrometer, Ccd camera, Observatory, law, Astronomy, High resolution, Astronomical telescopes, Remote sensing, law.invention
Abstract: The state of the telescope, now fully assembled and installed at the Helmos Observatory is presented. The completion of our new Transient Aristarchos Spectrometer (ATS), the arrival of the refurbished high resolution Manchester Echelle Spectrometer (MES‐AT) and the progress made towards the construction of the Vernikos‐Eugenides CCD Camera (VEC), in combination with our presence in OPTICON, maintain alive all our hopes for an eventual successful and fruitful international operation of the ARISTARCHOS telescope.
Published: 2006

34. Modelling the dust content of spiral galaxies: More dust mass vs. enhanced dust grain emissivity

Author: Kalliopi Dasyra, N. D. Kylafis, A. Misiriotis, and E. M. Xilouris
Subjects: Physics, Spiral galaxy, Astrophysics::High Energy Astrophysical Phenomena, Astrophysics (astro-ph), FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Galaxy, Stars, Thin disk, Emissivity, Radiative transfer, Spectral energy distribution, Astrophysics::Solar and Stellar Astrophysics, Surface brightness, Astrophysics::Earth and Planetary Astrophysics, Astrophysics::Galaxy Astrophysics
Abstract: We present detailed modelling of the spectral energy distribution (SED) of the spiral galaxies NGC 891, NGC 4013, and NGC 5907 in the far-infrared (FIR) and sub-millimeter (submm) wavelengths. The model takes into account the emission of the diffuse dust component, which is heated by the UV and optical radiation fields produced by the stars, as well as the emission produced locally in star forming HII complexes. The radiative transfer simulations of Xilouris et al. (1999) in the optical bands are used to constrain the stellar and dust geometrical parameters, as well as the total amount of dust. We find that the submm emission predicted by our model can not account for the observed fluxes at these wavelengths. We examine two cases, one having more dust embedded in a second thin disk and another allowing for an enhanced submillimeter emissivity of the dust grains. We argue that both cases can equally well reproduce the observed SED. The case of having more dust embedded in a second disk though, is not supported by the near-infrared observations and thus more realistic distributions of the dust (i.e., in spiral arms and clumps) have to be examined in order to better fit the surface brightness of each galaxy., To appear in the proceedings of: "The Spectral Energy Distribution of Gas-Rich Galaxies: Confronting Models with Data", Heidelberg, 4-8 Oct. 2004, eds. C.C. Popescu and R.J. Tuffs, AIP Conf. Ser., in press
Published: 2005

35. B and I-band optical micro-variability observations of the BL Lac objects S5 2007+777 and 3C371

Author: A. Dapergolas, P. Boumis, E. M. Xilouris, I. E. Papadakis, J. Alikakos, N. Smith, C. D. Goudis, and J. Papamastorakis
Subjects: Physics, Jet (fluid), I band, Astrophysics (astro-ph), Flux, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, B band, Light curve, Small amplitude, Amplitude, Space and Planetary Science
Abstract: We have observed S5 2007+777 and 3C371 in the B and I bands for 13 and 8 nights, respectively, during various observing runs in 2001, 2002 and 2004. The observations resulted in almost evenly sampled light curves, 6-9 hours long. We do not detect any flares within the observed light curves, but we do observe small amplitude, significant variations, in both bands, on time scales of hours and days. The average variability amplitude on time scales of minutes/hours is 2.5% and 1-1.5% in the case of S5 2007+777 and 3C371, respectively. The average amplitudes increase to 5-12% and 4-6%, respectively, on time scales of days. We find that the B and I band variations are highly correlated, on both short and long time scales. During the 2004 observations, which resulted in the longest light curves, we observe two well defined flux-decay and rising trends in the light curves of both objects. When the flux decays, we observe significant delays, with the B band flux decaying faster than the flux in the I band. As a result, we also observe significant, flux related spectral variations as well. The flux-spectral relation is rather complicated, with loop-like structures forming during the flux evolution. The presence of spectral variations imply that the observed variability is not caused by geometric effects. On the other hand, our results are fully consistent with the hypothesis that the observed variations are caused by perturbations which affect different regions in the jet of the sources., Comment: Accepted for publication in Astronomy and Astrophysics
Published: 2005
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36. Calculating the submillimeter emissivity of dust grains in spiral galaxies

Author: E. M. Xilouris
Subjects: Physics, Spiral galaxy, Amorphous carbon, Astrophysics (astro-ph), Thermal, Emissivity, FOS: Physical sciences, Astrophysics, Surface brightness, Galaxy, Optical depth, Amorphous solid
Abstract: We use the radiation transfer simulation of Xilouris et al. (1999) to constrain the quantity of dust in three nearby spiral galaxies (NGC 4013, NGC 5907 and NGC 891). The predicted visual optical depth from the model is compared with the thermal continuum radiation detected from these galaxies at 850 microns. This comparison yields the emissivity of dust grains in the submillimeter waveband which is a factor 4 higher than the benchmark, semi-empirical model of Draine & Lee (1984). Our estimates are more closely aligned with recent measurements carried out in the laboratory on amorphous carbon and silicate particulates. A comparison between the distribution of 850 microns surface brightness and the intensity levels in the ^{12}CO(1-0) and 21 cm lines underlines the spatial association between dust detected in the submillimeter waveband and molecular gas clouds. We suggest that the relatively high emissivity values that we derive may be attributable to amorphous, fluffy grains situated in denser gas environments., To appear in the proceedings of: "The Spectral Energy Distribution of Gas-Rich Galaxies: Confronting Models with Data", Heidelberg, 4-8 Oct. 2004, eds. C.C. Popescu and R.J. Tuffs, AIP Conf. Ser., in press
Published: 2005

37. Determination of the 3D Dust Distribution in Spiral Galaxies

Author: E. M. Xilouris and N. D. Kylafis
Subjects: Physics, Barred spiral galaxy, Spiral galaxy, Bulge, Elliptical galaxy, Astrophysics::Cosmology and Extragalactic Astrophysics, Grand design spiral galaxy, Astrophysics, Disc, Lenticular galaxy, Astrophysics::Galaxy Astrophysics, Dust lane
Abstract: The amount and distribution of dust in spiral galaxies remains an unsolved problem. For its solution, two approaches appear to be promising: The small N approach and the large None.
Published: 1996

38. ERRATUM: 'THE MOLECULAR GAS IN LUMINOUS INFRARED GALAXIES. II. EXTREME PHYSICAL CONDITIONS AND THEIR EFFECTS ON THEXcoFACTOR' (2012, ApJ, 751, 10)

Author: K. G. Isaak, Padelis P. Papadopoulos, Paul van der Werf, E. M. Xilouris, and Yu Gao
Subjects: Luminous infrared galaxy, Physics, Space and Planetary Science, Co factor, Astronomy, Astronomy and Astrophysics, Astrophysics
Published: 2012

39. Low-mass x-ray binary models for the supersoft x-ray sources in the large magellanic cloud

Author: E. M. Xilouris and N. D. Kylafis
Subjects: Physics, Accretion (meteorology), Astrophysics::High Energy Astrophysical Phenomena, X-ray binary, Astronomy, Local Group, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, Spectral line, Luminosity, Neutron star, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Low Mass, Large Magellanic Cloud, Astrophysics::Galaxy Astrophysics
Abstract: We propose that the supersoft x‐ray spectra observed in CAL 83, CAL 87, and RX J0527.8‐6954 can be explained as a result of near‐Eddington accretion onto neutron stars. Our model is consistent with a recently proposed unified model for the low‐mass x‐ray binaries (LMXRB). If the luminosity of the source is within 10% of the Eddington value, what determines whether the source appears as a supersoft x‐ray source or as a ‘‘canonical’’ LMXRB is the nature of the accretion flow and its extend. If the radial flow is subsonic and extends to at least a few thousand neutron star radii the source behaves like a supersoft one. If on the other hand the flow is supersonic and extends to at most a few hundred neutron star radii, the source exhibits the characteristics of a ‘‘canonical’’ LMXRB.
Published: 1994

40. The GALEX Ultraviolet Virgo Cluster Survey (GUViCS). I: The UV luminosity function of the central 12 sq.deg

Author: Laura Ferrarese, Emmanuel Momjian, Leslie K. Hunt, Eric Emsellem, J. I. Davies, Catherine Vlahakis, José M. Solanes, Noah Brosch, Matthew Smith, Jacopo Fritz, Andrés Jordán, Kelley M. Hess, James E. Taylor, W. van Driel, I. De Looze, Marco Grossi, Samuel Boissier, Patrick R. Durrell, Maarten Baes, Alessandro Boselli, S. di Serego Alighieri, Thomas Erben, Simona Mei, Sebastien Heinis, Pierre-Alain Duc, Thomas M. Hughes, Emmanuel M. Xilouris, O. Spector, Brian R. Kent, D. A. Garcia-Appadoo, Emmanouil Papastergis, Giuseppe Gavazzi, C. Balkowski, Bernd Vollmer, Kristine Spekkens, O. Ilbert, Laura Magrini, Lauren A. MacArthur, Riccardo Giovanelli, O. Cucciati, Suzanne C. Madden, Ariane Lançon, Marcel Clemens, C. Valotto, Vassilis Charmandaris, Luca Cortese, Marc Huertas-Company, Martha P. Haynes, Joris Verstappen, Scott Chapman, Aliakbar Dariush, Diego G. Lambas, Ronald P. Olowin, Astronomy, Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), A. Boselli, S. Boissier, S. Heini, L. Cortese, O. Ilbert, T. Hughe, O. Cucciati, J. Davie, L. Ferrarese, R. Giovanelli, M. P. Hayne, M. Bae, C. Balkowski, N. Brosch, S. C. Chapman, V. Charmandari, M. S. Clemen, A. Dariush, I. De Looze, S. di Serego Alighieri, P.-A. Duc, P. R. Durrell, E. Emsellem, T. Erben, J. Fritz, D. A. Garcia-Appadoo, G. Gavazzi, M. Grossi, A. Jordán, K. M. He, M. Huertas-Company, L. K. Hunt, B. R. Kent, D. G. Lamba, A. Lançon, L. A. MacArthur, S. C. Madden, L. magrini, S. Mei, E. Momjian, R. P. Olowin, E. Papastergi, M. W. L. Smith, J. M. Solane, O. Spector, K. Spekken, J. E. Taylor, C. Valotto, W. van Driel, J. Verstappen, C. Vlahaki, B. Vollmer, and E. M. Xilouris
Subjects: HI SOURCE CATALOG, Cosmology and Nongalactic Astrophysics (astro-ph.CO), COMA CLUSTER, FAST ALPHA SURVEY, DATA RELEASE, NEARBY CLUSTERS, FOS: Physical sciences, DWARF ELLIPTIC GALAXIES, Astrophysics, medicine.disease_cause, 01 natural sciences, Luminosity, STAR-FORMATION, 0103 physical sciences, Galaxy formation and evolution, medicine, Cluster (physics), fundamental parameters [galaxies], EARLY-TYPE GALAXIES, 010303 astronomy & astrophysics, galaxies: fundamental parameter, evolution [galaxies], Luminosity function (astronomy), luminosity function [galaxies], Physics, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], 010308 nuclear & particles physics, Star formation, Astronomy and Astrophysics, galaxies: fundamental parameters, clusters: individual: Virgo [galaxies], BAND SURFACE PHOTOMETRY, Virgo Cluster, Galaxy, galaxies: luminosity function, Physics and Astronomy, Space and Planetary Science, mass function, galaxies: luminosity function, mass function, galaxies: clusters: individual: Virgo, ultraviolet: galaxies, astro-ph.CO, ultraviolet: galaxie, DIGITAL SKY SURVEY, galaxies [ultraviolet], galaxies: evolution, Ultraviolet, Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract: The GALEX Ultraviolet Virgo Cluster Survey (GUViCS) is a complete blind survey of the Virgo cluster covering about 40 sq. deg. in the far UV (FUV, lambda_eff=1539A, Delta-lambda=442A) and about 120 sq. deg. in the near UV (NUV, lambda_eff=2316A, Delta-lambda=1060A). The goal of the survey is to study the ultraviolet (UV) properties of galaxies in a rich cluster environment, spanning a wide luminosity range from giants to dwarfs, and regardless of prior knowledge of their star formation activity. The UV data will be combined with those in other bands (optical: NGVS; far-infrared - submm: HeViCS; HI: ALFALFA) and with our multizone chemo-spectrophotometric models of galaxy evolution to make a complete and exhaustive study of the effects of the environment on the evolution of galaxies in high density regions. We present here the scientific objectives of the survey, describing the observing strategy and briefly discussing different data reduction techniques. Using UV data already in-hand for the central 12 sq. deg. we determine the FUV and NUV luminosity functions of the Virgo cluster core for all cluster members and separately for early- and late-type galaxies and compare it to the one obtained in the field and other nearby clusters (Coma, A1367). This analysis shows that the FUV and NUV luminosity functions of the core of the Virgo clusters are flatter (alpha about -1.1) than those determined in Coma and A1367. We discuss the possible origin of this difference, 18 pages, 14 figures, accepted in A&A, high resolution version of figure 1 and 2 and other information available at http://galex.oamp.fr/guvics/observations.html
Published: 2011

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