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38 results on '"individual objects"'

1. Magnetic fields and outflows in the large Bok globule CB 54

Author: Kate Pattle, Shih-Ping Lai, Sarah Sadavoy, Simon Coudé, Sebastian Wolf, Ray Furuya, Woojin Kwon, Chang Won Lee, and Niko Zielinski
Subjects: stars, individual objects, magnetic fields –submillimetre, Space and Planetary Science, CB 54 –ISM, Astrophysics of Galaxies (astro-ph.GA), formation –ISM, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics - Astrophysics of Galaxies, Astrophysics::Galaxy Astrophysics, ISM
Abstract: We have observed the large Bok globule CB 54 in 850$μ$m polarised light using the POL-2 polarimeter on the James Clerk Maxwell Telescope (JCMT). We find that the magnetic field in the periphery of the globule shows significant, ordered deviation from the mean field direction in the globule centre. This deviation appears to correspond with the extended but relatively weak $^{12}$CO outflow emanating from the Class 0 sources at the centre of the globule. Energetics analysis suggests that if the outflow is reshaping the magnetic field in the globule's periphery, then we can place an upper limit of $ 0.1$ pc., 11 pages, 10 figures, accepted for publication in Monthly Notices of the Royal Astronomical Society (MNRAS)
Published: 2022

2. Characterizing the PAH emission in the Orion Bar

Author: C. Knight, Els Peeters, William D. Vacca, and Alexander G. G. M. Tielens
Subjects: individual objects, Orion Bar, 010504 meteorology & atmospheric sciences, Infrared, photodissociation region (PDR), FOS: Physical sciences, chemistry.chemical_element, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, Photodissociation region, spectroscopic, 01 natural sciences, Spectral line, Neon, Spitzer Space Telescope, Ionization, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, ISM, 0105 earth and related environmental sciences, Physics, astrochemistry, Stratospheric Observatory for Infrared Astronomy, Astronomy and Astrophysics, Astrophysics - Astrophysics of Galaxies, chemistry, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), infrared, techniques, Bar (unit)
Abstract: We present 5--14~$\mu$m spectra at two different positions across the Orion Bar photodissociation region (PDR) obtained with the Infrared Spectrograph onboard the Spitzer Space Telescope and 3.3~$\mu$m PAH observations obtained with the Stratospheric Observatory for Infrared Astronomy (SOFIA). We aim to characterize emission from Polycyclic Aromatic Hydrocarbon (PAH), dust, atomic and molecular hydrogen, argon, sulfur, and neon as a function of distance from the primary illuminating source. We find that all the major PAH bands peak between the ionization front and the PDR front, as traced by H$_{2}$, while variations between these bands become more pronounced moving away from this peak into the face-on PDRs behind the PDR front and at the backside of the \HII\, region. While the relative PAH intensities are consistent with established PAH characteristics, we report unusual behaviours and attribute these to the PDR viewing angle and the strength of the FUV radiation field impinging on the PDRs. We determine the average PAH size which varies across the Orion Bar. We discuss subtle differences seen between the cationic PAH bands and highlight the photo-chemical evolution of carbonaceous species in this PDR environment. We find that PAHs are a good tracer of environmental properties such as the strength of the FUV radiation field and the PAH ionization parameter., Comment: 25 pages, 19 Figures. To be published in MNRAS
Published: 2021

3. Deuteration of c-C3H2 towards the pre-stellar core L1544

Author: Giers, K., Spezzano, S., Alves, F., Caselli, P., Redaelli, E., Sipilä, O., Khalifa, M. Ben, Wiesenfeld, L., Brünken, S., Bizzocchi, L., K. Gier, S. Spezzano, F. Alve, P. Caselli, E. Redaelli, O. Sipilä, M. Ben Khalifa, L. Wiesenfeld, S. Brünken, and L. Bizzocchi
Subjects: stars, individual objects, IONS, STARLESS CORES, FOS: Physical sciences, clouds, Astronomy & Astrophysics, RING MOLECULE C3H2, star, RADIATIVE-TRANSFER, CHEMISTRY, ABUNDANCE RATIO, cloud, molecules, ISM, molecule, abundance, Science & Technology, astrochemistry, abundances, formation, N2H+, Astronomy and Astrophysics, FELIX Infrared and Terahertz Spectroscopy, Astrophysics - Astrophysics of Galaxies, individual object, DEUTERIUM FRACTIONATION, L1544, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), Physical Sciences, DEPLETION, CYCLOPROPENYLIDENE
Abstract: Context: In the centre of pre-stellar cores, the deuterium fractionation is enhanced due to the cold temperatures and high densities. Therefore, the chemistry of deuterated molecules can be used to probe the evolution and the kinematics in the earliest stages of star formation. Aims: We analyse emission maps of cyclopropenylidene, c-C$_3$H$_2$, to study the distribution of the deuteration throughout the prototypical pre-stellar core L1544. Methods: We use single-dish observations of c-C$_3$H$_2$, c-H$^{13}$CC$_2$H, c-C$_3$HD, and c-C$_3$D$_2$ towards the pre-stellar core L1544, performed at the IRAM 30m telescope. We derive the column density and deuterium fraction maps, and compare these observations with non-LTE radiative transfer simulations. Results: The highest deuterium fractions are found close to the dust peak at the centre of L1544, where the increased abundance of H$_2$D$^+$ ions drives the deuteration process. The peak values are N(c-C$_3$HD)/N(c-C$_3$H$_2)=0.17\pm0.01$, N(c-C$_3$D$_2$)/N(c-C$_3$H$_2)=0.025\pm0.003$ and N(c-C$_3$D$_2$)/N(c-C$_3$HD$)=0.16\pm0.03$, which is consistent with previous single point observations. The distributions of c-C$_3$HD and c-C$_3$D$_2$ indicate that the deuterated forms of c-C$_3$H$_2$ in fact trace the dust peak and not the c-C$_3$H$_2$ peak. Conclusions: The N(c-C$_3$D$_2$)/N(c-C$_3$HD) map confirms that the process of deuteration is more efficient towards the centre of the core and demonstrates that carbon-chain molecules are still present at high densities. This is likely caused by an increased abundance of He$^+$ ions destroying CO, which increases the amount of carbon atoms in the gas phase., 13 pages, 9 figures
Published: 2022

4. Discovery of CH3CHCO in TMC-1 with the QUIJOTE line survey

Author: R. Fuentetaja, C. Bermúdez, C. Cabezas, M. Agúndez, B. Tercero, N. Marcelino, J. R. Pardo, L. Margulès, R. A. Motiyenko, J.-C. Guillemin, P. de Vicente, J. Cernicharo, Consejo Superior de Investigaciones Científicas [Spain] (CSIC), Universidad de Valladolid [Valladolid] (UVa), Instituto Geografico Nacional (IGN), Laboratoire de Physique des Lasers, Atomes et Molécules - UMR 8523 (PhLAM), Université de Lille-Centre National de la Recherche Scientifique (CNRS), Institut des Sciences Chimiques de Rennes (ISCR), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Ministerio de Ciencia e Innovacion of Spain (MICIU) [PID2019-106110GB-I00, ERC-2013-Syg-610256-NANOCOSMOS], ERC [CONVREC-2021-317], Ministerio de Universidades [PID2019-107115GB-C21], and [PID2019-106235GB-I00]
Subjects: individual objects, molecular data, astrochemistry, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics - Astrophysics of Galaxies, TMC-1, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), identification, [CHIM]Chemical Sciences, line, molecules, ISM
Abstract: We report the detection of methyl ketene towards TMC-1 with the QUIJOTE line survey. Nineteen rotational transitions with rotational quantum numbers ranging from J = 3 up to J = 5 and Ka ≤ 2 were identified in the frequency range 32.0–50.4 GHz, 11 of which arise above the 3σ level. We derived a column density for CH3CHCO of N = 1.5 × 1011 cm−2 and a rotational temperature of 9 K. Hence, the abundance ratio between ketene and methyl ketene, CH2CO/CH3CHCO, is 93. This species is the second C3H4O isomer detected. The other, trans-propenal (CH2CHCHO), corresponds to the most stable isomer and has a column density of N = (2.2 ± 0.3)×1011 cm−2, which results in an abundance ratio CH2CHCHO/CH3CHCO of 1.5. The next non-detected isomer with the lowest energy is cis-propenal, which is therefore a good candidate for future discovery. We have carried out an in-depth study of the possible gas-phase chemical reactions involving methyl ketene to explain the abundance detected, achieving good agreement between chemical models and observations.
Published: 2023

5. The sharp ALMA view of infall and outflow in the massive protocluster G31.41+0.31

Author: M. T. Beltrán, V. M. Rivilla, R. Cesaroni, D. Galli, L. Moscadelli, A. Ahmadi, H. Beuther, S. Etoka, C. Goddi, P. D. Klaassen, R. Kuiper, M. S. N. Kumar, A. Lorenzani, T. Peters, Á. Sánchez-Monge, P. Schilke, F. van der Tak, S. Vig, and Astronomy
Subjects: Interferometric, stars: formation, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Stars - massive, Physik (inkl. Astronomie), Astrophysics - Astrophysics of Galaxies, Techniques, Individual objects, stars: massive, G31.41+0.31, Space and Planetary Science, techniques: interferometric, Astrophysics of Galaxies (astro-ph.GA), Astrophysics::Solar and Stellar Astrophysics, Stars - formation, Astrophysics::Earth and Planetary Astrophysics, ISM: individual objects: G31.41+0.31, Astrophysics::Galaxy Astrophysics, ISM
Abstract: Context. To better understand the formation of high-mass stars, it is fundamental to investigate how matter accretes onto young massive stars, how it is ejected, and how all this differs from the low-mass case. The massive protocluster G31.41+0.31 is the ideal target to study all these processes because observations at millimeter and centimeter wavelengths have resolved the emission of the Main core into at least four massive dust continuum sources, named A, B, C, and D, within 1" or 0.018 pc, and have identified signatures of infall and several outflows associated with the core. Aims. We study the interplay between infall and outflow in G31.41+0.31 by investigating at a spatial resolution of a few 100 au their properties and their possible impact on the core. Methods. We carried out molecular line observations of typical high-density tracers, such as CH3CN or H2CO, and shock and outflow tracers, such as SiO, with ALMA at 1.4 mm that achieved an angular resolution of 0.09" (340 au). Results. The observations have revealed inverse P-Cygni profiles in CH3CN and H2CO toward the four sources embedded in the Main core, suggesting that all of them are undergoing collapse. The infall rates, estimated from the red-shifted absorption are on the order of 1E-2 Msun/yr. The individual infall rates imply that the accretion timescale of the Main core is an order of magnitude smaller than its rotation timescale. This confirms that rotating toroids such as the G31 Main core are non-equilibrium, transient collapsing structures that need to be constantly replenished with fresh material from a large-scale reservoir. For sources B, C, and D, the infall could be accelerating inside the sources, while for source A, the presence of a second emission component complicates the interpretation. The SiO observations have revealed the presence of at least six outflows in the G31.41+0.31 star-forming region, ..., 17 pages, 9 figures, 2 tables. Accepted by A&A
Published: 2022

6. Orion Bar as a Window to the Evolution of PAHs

Author: Murga, M. S., Kirsanova, M. S., Wiebe, D. S., and Boley, P. A.
Subjects: ATOMS, ASTROCHEMISTRY, MID-INFRARED EMISSION, POLYCYCLIC AROMATIC HYDROCARBONS, TELESCOPES, INFRARED, LINES AND BANDS, OBSERVATORIES, INDIVIDUAL OBJECTS, ORION BAR, EVOLUTION, ISM
Abstract: We investigate the mid-infrared (IR) emission in the Orion Bar photodissociation region (PDR), using archival photometric and spectroscopic observations from the United Kingdom Infrared Telescope (UKIRT), Spitzer, Infrared Space Observatory(ISO), and Stratospheric Observatory for Infrared Astronomy (SOFIA) telescopes. Specifically, we consider flux densities of the emission bands at 3.3, 3.4, 3.6, 6.6, 7.7, and 11.2 $$m in several locations and a spectrum from 3 to 45 $$m in one location. We study the behaviour of band flux ratios, which are sensitive to external conditions, as revealed by their variations with the distance from an ionizing source. Assuming that the mid-IR emission arises mostly from polycyclic aromatic hydrocarbons (PAHs), and that a weak emission feature at 3.4 $$m is related to PAHs with extra hydrogen atoms (H-PAHs), we trace variations of the ratios using a model for PAH evolution. Namely, we estimate how populations of PAHs of different sizes, hydrogenation and ionization states change across the Orion Bar over a time interval approximately equal to its lifetime. The obtained ensembles of PAHs are further used to calculate the corresponding synthetic spectra and band flux densities. The model satisfactorily describes the main features of the ratios I3.6/I11.2, I7.7/I11.2, I7.7/I3.6, and I3.3/I3.4. We conclude that the best coincidence between modelling and observations is achieved if C loss of PAHs is limited by the number of carbon atoms NC = 60, and the band at 3.4 $$m may indeed be attributed to H-PAHs. We confi that large cations dominate at the surface of the PDR but small neutral PAHs and anions are abundant deeper in the molecular cloud. © 2021 The Author(s) Published by Oxford University Press on behalf of Royal Astronomical Society.
Published: 2022

7. The peculiar nebula Simeis 57: II. Distance, nature and excitation

Author: P. T. Boyd, Jarle Brinchmann, T. R. Gull, John Bally, Anthony G. A. Brown, Frank P. Israel, L. H. T. Oudshoorn, and M. B. C. Kloppenburg
Subjects: Individual Objects, Star (game theory), Astrophysics::High Energy Astrophysical Phenomena, Extinction (astronomy), FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, 010303 astronomy & astrophysics, ISM, Astrophysics::Galaxy Astrophysics, Physics, Nebula, 010308 nuclear & particles physics, Molecular cloud, HII Regions, Structure, Astronomy and Astrophysics, Astrophysics - Astrophysics of Galaxies, Stars, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), Simeis 57, Astrophysics::Earth and Planetary Astrophysics, Supergiant, Excitation
Abstract: Simeis 57 (HS 191) is an optically bright nebula in the Cygnus X region with a peculiar appearance that suggests an outflow from a rotating source. Newly obtained observations and archival data reveal Simeis 57 as a low-density (ne ~ 100 cm−3) nebula with an east-to-west excitation gradient. The extinction of the nebula is AV ≤ 2 mag. The nebula is recognizable but not prominent in mid- and far-infrared images. In its direction, half a dozen small CO clouds have been identified at VLSR = +5 km s−1. One of these coincides with both the optical nebula and a second CO cloud at the nebular velocity VLSR ≈−10 km−1. No luminous stars are embedded in these molecular clouds, nor are any obscured by them and no sufficiently luminous stars are found in the immediate vicinity of the nebula. Instead, all available data points to the evolved star HD 193793 = WR 140 (an O4-5 supergiant and WC7 Wolf–Rayet binary) as the source of excitation, notwithstanding its large separation of 50′, about 25 pc at the stellar distance of 1.7 kpc. Simeis 57 appears to be a part of a larger structure surrounding the HI void centered on HD 193793.
Published: 2021

8. Discovery of the acetyl cation, CH3CO+, in space and in the laboratory

Author: Nuria Marcelino, P. de Vicente, José Cernicharo, Celina Bermúdez, Roman A. Motiyenko, Belén Tercero, Bertrand Lefloch, Carlos Cabezas, Laurent Margulès, Marcelino Agúndez, Luyao Zou, S. Bailleux, Yasuki Endo, Laboratoire de Physique des Lasers, Atomes et Molécules - UMR 8523 (PhLAM), Université de Lille-Centre National de la Recherche Scientifique (CNRS), Physique Moléculaire aux Interfaces (PMI), Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), Université de Lille, Agencia Estatal de Investigación (España), European Commission, Ministry of Science and Technology (Taiwan), Instituto de Física Fundamental [Madrid] (IFF), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), and National Chiao Tung University (NCTU)
Subjects: individual objects, Abundance (chemistry), Line: identification, Analytical chemistry, FOS: Physical sciences, Ketene, TMC-1 -line, Protonation, Astrophysics, Space (mathematics), 01 natural sciences, chemistry.chemical_compound, astrochemistry -ISM, Ab initio quantum chemistry methods, 0103 physical sciences, identification [Line], ISM: individual objects: TMC-1, 010306 general physics, 010303 astronomy & astrophysics, molecules [ISM], Astrochemistry, Physics, Molecular data, molecules -ISM, Astronomy and Astrophysics, identification -molecular data, Intensity ratio, Astrophysics - Astrophysics of Galaxies, ISM: molecules, Symmetry (physics), individual objects: TMC-1 [ISM], chemistry, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), Proton affinity, [SDU.ASTR.GA]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Galactic Astrophysics [astro-ph.GA], [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract: 12 pags., 6 figs., 7 tabs., Using the Yebes 40 m and IRAM 30 m radiotelescopes, we detected two series of harmonically related lines in space that can be fitted to a symmetric rotor. The lines have been seen towards the cold dense cores TMC-1, L483, L1527, and L1544. High level of theory ab initio calculations indicate that the best possible candidate is the acetyl cation, CH3CO+, which is the most stable product resulting from the protonation of ketene. We have produced this species in the laboratory and observed its rotational transitions Ju = 10 up to Ju = 27. Hence, we report the discovery of CH3CO+ in space based on our observations, theoretical calculations, and laboratory experiments. The derived rotational and distortion constants allow us to predict the spectrum of CH3CO+ with high accuracy up to 500 GHz. We derive an abundance ratio N(H2CCO)/N(CH3CO+) ∼44. The high abundance of the protonated form of H2CCO is due to the high proton affinity of the neutral species. The other isomer, H2CCOH+, is found to be 178.9 kJ mol-1 above CH3CO+. The observed intensity ratio between the K = 0 and K = 1 lines, ∼2.2, strongly suggests that the A and E symmetry states have suffered interconversion processes due to collisions with H and/or H2, or during their formation through the reaction of H3+ with H2CCO., The Spanish authors thank Ministerio de Ciencia e Innovación for funding support through project AYA2016-75066-C2-1-P, PID2019- 106235GB-I00 and PID2019-107115GB-C21/AEI/10.13039/501100011033. We also thank ERC for funding through grant ERC-2013-Syg-610256- NANOCOSMOS. MA and CB thanks Ministerio de Ciencia e Innovación for grants RyC-2014-16277 and FJCI-2016-27983, respectively. Y. Endo thanks Ministry of Science and Technology of Taiwan through grant MOST108-2113- M-009-25.
Published: 2021

9. XI. First measurement of nitrogen fractionation in shocked clumps of the L1157 protostellar outflow

Author: Benedettini, M., Viti, S., Codella, C., Ceccarelli, C., Neri, R., López-Sepulcre, A., Bianchi, E., Busquet, G., Caselli, P., Fontani, F., Lefloch, B., Podio, L., Spezzano, S., Vastel, C., Istituto di Astrofisica e Planetologia Spaziali - INAF (IAPS), Istituto Nazionale di Astrofisica (INAF), University College of London [London] (UCL), INAF - Osservatorio Astrofisico di Arcetri (OAA), Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), Centre National d'Études Spatiales [Toulouse] (CNES)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), 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)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-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)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA), Institut de RadioAstronomie Millimétrique (IRAM), Centre National de la Recherche Scientifique (CNRS), Istituti di Ricovero e Cura a Carattere Scientifico (IRCCS), and Max-Planck-Institut für Extraterrestrische Physik (MPE)
Subjects: individual objects, L1157, molecules -ISM, jets and outflow, [SDU.ASTR.GA]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Galactic Astrophysics [astro-ph.GA], ISM
Abstract: International audience; Context. The isotopic ratio of nitrogen presents a wide range of values in the Solar System: from ∼140 in meteorites and comets to 441 in the solar wind. In star-forming systems, we observe even a higher spread of ∼150-1000. The origin of these differences is still unclear. Aims. Chemical reactions in the gas phase are one of the possible processes that could modify the 14 N/ 15 N ratio. We aim to investigate if and how the passage of a shock wave in the interstellar medium, which activates a rich chemistry, can affect the relative fraction of nitrogen isotopes. The ideal place for such a study is the chemically rich outflow powered by the L1157-mm protostar, where several shocked clumps are present. Methods. We present the first measurement of the 14 N/ 15 N ratio in the two shocked clumps, B1 and B0, of the protostellar outflow L1157. The measurement is derived from the interferometeric maps of the H 13 CN (1-0) and the HC 15 N (1-0) lines obtained with the NOrthern Extended Millimeter Array (NOEMA) interferometer as part of the Seeds of Life in Space (SOLIS) programme. Results. In B1, we find that the H 13 CN (1-0) and HC 15 N (1-0) emission traces the front of the clump, that is the apex of the shocked region, where the fast jet impacts the lower velocity medium with an averaged column density of N(H 13 CN) ∼ 7 × 10 12 cm −2 and N(HC 15 N) ∼ 2 × 10 12 cm −2. In this region, the ratio H 13 CN (1-0)/HC 15 N (1-0) is almost uniform with an average value of ∼5 ± 1. The same average value is also measured in the smaller clump B0e. Assuming the standard 12 C/ 13 C = 68, we obtain 14 N/ 15 N = 340 ± 70. This ratio is similar to those usually found with the same species in prestellar cores and protostars. We analysed the prediction of a chemical shock model for several shock conditions and we found that the nitrogen and carbon fractionations do not vary much for the first period after the shock. The observed H 13 CN/HC 15 N can be reproduced by a non-dissociative, C-type shock with pre-shock density n(H) = 10 5 cm −3 , shock velocity V s between 20 and 40 km s −1 , and cosmic-ray ionization rate of 3 × 10 −16 s −1 ; this agrees with previous modelling of other chemical species in L1157-B1. Conclusions. Both observations and chemical models indicate that the rich chemistry activated by the shock propagation does not affect the nitrogen isotopic ratio, which remains similar to that measured in lower temperature gas in prestellar cores and protostellar envelopes.
Published: 2021

10. Successive deuteration in low-mass star-forming regions: The case of D2-methanol (CHD2OH) in IRAS 16293-2422

Author: Drozdovskaya, Maria N., Coudert, Laurent H., Margulès, Laurent, Coutens, Audrey, Jørgensen, Jes K., Manigand, Sébastien, Center for Space and Habitability, Institut des Sciences Moléculaires d'Orsay (ISMO), Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique des Lasers, Atomes et Molécules - UMR 8523 (PhLAM), Université de Lille-Centre National de la Recherche Scientifique (CNRS), Physique Moléculaire aux Interfaces (PMI), Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), 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), Niels Bohr Institute [Copenhagen] (NBI), Faculty of Science [Copenhagen], University of Copenhagen = Københavns Universitet (UCPH)-University of Copenhagen = Københavns Universitet (UCPH), 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, and 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)
Subjects: individual objects, ALMA-PILS SURVEY, 530 Physics, FOS: Physical sciences, LINE SURVEY, 1ST DETECTION, FAR-INFRARED SPECTRUM, astrochemistry -ISM, molecules -Stars, ISM [submillimeter], INTERNAL AXIS APPROACH, Solar and Stellar Astrophysics (astro-ph.SR), molecules [ISM], protostars [stars], ISM, Earth and Planetary Astrophysics (astro-ph.EP), formation -ISM, formation [stars], [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], astrochemistry, 520 Astronomy, H-D-SUBSTITUTION, Astronomy and Astrophysics, TORSIONAL ROTATIONAL SPECTRA, 500 Science, Astrophysics - Astrophysics of Galaxies, DEUTERIUM FRACTIONATION, protostars -Stars, IRAS 16293-2422 -Submillimeter, individual objects: IRAS 16293-2422 [ISM], Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), ORGANIC-MOLECULES, ASYMMETRIC ASYMMETRIC MOLECULES, Astrophysics - Earth and Planetary Astrophysics
Abstract: Accurate quantification of the column density of di-deuterated methanol is a key missing puzzle piece in the otherwise thoroughly constrained family of D-bearing methanol in the deeply embedded low-mass protostellar system and astrochemical template source IRAS16293-2422. A spectroscopic dataset for astrophysical purposes is built for CHD$_{2}$OH and made publicly available to facilitate accurate characterization of this species in astrochemical surveys. The newly computed line list and partition function are used to search for CHD$_{2}$OH towards IRAS16293-2422 A and B in data from ALMA-PILS. Only non-blended, optically thin lines of CHD$_{2}$OH are used for the synthetic spectral fitting. The constructed spectroscopic database contains line frequencies and strengths for 7417 transitions in the 0 to 500 GHz frequency range. ALMA-PILS observations in the 329-363 GHz range are used to identify 105 unique, non-blended, optically thin line frequencies of CHD$_{2}$OH for synthetic spectral fitting. The derived excitation temperatures and column densities yield high D/H ratios of CHD$_{2}$OH in IRAS 16293-2422 A and B of 7.5$\pm$1.1% and 7.7$\pm$1.2%, respectively. Deuteration in IRAS 16293-2422 is not higher than in other low-mass star-forming regions. Di-deuterated molecules consistently have higher D/H ratios than their monodeuterated counterparts in all low-mass protostars, which may be a natural consequence of H-D substitution reactions as seen in laboratory experiments. The Solar System's natal cloud, as traced by comet 67P/Churyumov-Gerasimenko, may have had a lower initial abundance of D, been warmer than the cloud of IRAS16293-2422, or been partially reprocessed. In combination with accurate spectroscopy, a careful spectral analysis, and a consideration of the underlying assumptions, successive deuteration is a robust window on the physicochemical provenance of star-forming systems., Accepted for publication in A&A; 24 pages, 18 figures, 3 tables; the full line list is made available as an electronic Table at the Centre de Donn\'ees astronomiques de Strasbourg (CDS) with association to this A&A article
Published: 2022

11. VERITAS Detection of LS 5039 and HESS J1825-137

Author: Olivier Hervet, Dirk Pandel, Marita Krause, John L. Quinn, G. Hughes, P. T. Reynolds, Ralph Bird, Tarek M. Hassan, David Kieda, Jodi Christiansen, P. Wilcox, D. S. Hanna, K. Ragan, Wystan Benbow, I. Sadeh, A. Weinstein, M. Pohl, Anushka Udara Abeysekara, Marcos Santander, R. A. Ong, M. J. Lang, A. D. Falcone, Wei Cui, Jamie Holder, M. Kertzman, T. B. Humensky, Robert Brose, M. K. Daniel, R. R. Prado, N. Kelley-Hoskins, P. Kar, David A. Williams, Lucy Fortson, P. Kaaret, M. Nievas-Rosillo, T. J. Williamson, G. H. Sembroski, E. Pueschel, Gernot Maier, P. Moriarty, A. J. Chromey, Gordon T. Richards, E. Roache, Daniel Nieto, U.S. Department of Energy Office of Science, National Science Foundation, Smithsonian Institution, and Natural Sciences and Engineering Research Council of Canada
Subjects: individual objects, stars, Open science, HESS J1825-137, Smithsonian institution, VHE [gamma ray], FOS: Physical sciences, Library science, 01 natural sciences, Technical support, star, HESS, 0103 physical sciences, User Facility, close, individual, 010303 astronomy & astrophysics, ISM, pulsar, High Energy Astrophysical Phenomena (astro-ph.HE), Physics, 010308 nuclear & particles physics, Astronomy and Astrophysics, gamma rays, flux, inverse scattering method, Work (electrical), binary [gamma ray], general, ddc:540, LS 5039, VERITAS, Astrophysics - High Energy Astrophysical Phenomena, binaries, statistical
Abstract: With 8 hours of observations, VERITAS confirms the detection of two very high energy gamma-ray sources. The gamma-ray binary LS 5039 is detected with a statistical significance of $8.8\sigma$. The measured flux above 1 TeV is $(2.5 \pm 0.4) \times 10^{-12} \rm \, cm^{-2} \, s^{-1}$ near inferior conjunction and $(7.8 \pm 2.8) \times 10^{-13} \rm \, cm^{-2} \, s^{-1}$ near superior conjunction. The pulsar wind nebula HESS J1825-137 is detected with a statistical significance of $6.7\sigma$ and a measured flux above 1 TeV of $(3.9 \pm 0.8) \times 10^{-12} \rm \, cm^{-2} \, s^{-1}$., Comment: 4 pages, 2 figures
Published: 2020

12. Seeds of Life in Space (SOLIS): VI. Chemical evolution of sulfuretted species along the outflows driven by the low-mass protostellar binary NGC 1333-IRAS4A

Author: V. Taquet, C. Codella, M. De Simone, A. López-Sepulcre, J. E. Pineda, D. Segura-Cox, C. Ceccarelli, P. Caselli, A. Gusdorf, M. V. Persson, F. Alves, E. Caux, C. Favre, F. Fontani, R. Neri, Y. Oya, N. Sakai, C. Vastel, S. Yamamoto, R. Bachiller, N. Balucani, E. Bianchi, L. Bizzocchi, A. Chacón-Tanarro, F. Dulieu, J. Enrique-Romero, S. Feng, J. Holdship, B. Lefloch, A. Jaber Al-Edhari, I. Jiménez-Serra, C. Kahane, V. Lattanzi, J. Ospina-Zamudio, L. Podio, A. Punanova, A. Rimola, I. R. Sims, S. Spezzano, L. Testi, P. Theulé, P. Ugliengo, A. I. Vasyunin, F. Vazart, S. Viti, A. Witzel, Istituto Nazionale di Astrofisica (INAF), Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), Centre National d'Études Spatiales [Toulouse] (CNES)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), 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)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-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)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA), Max Planck Institute for Extraterrestrial Physics (MPE), Max-Planck-Gesellschaft, Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA (UMR_8112)), Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-CY Cergy Paris Université (CY), Chalmers University of Technology [Göteborg], Centre National d'Études Spatiales [Toulouse] (CNES), Institut de recherche en astrophysique et planétologie (IRAP), Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), Institut de RadioAstronomie Millimétrique (IRAM), Centre National de la Recherche Scientifique (CNRS), The University of Tokyo (UTokyo), RIKEN - Institute of Physical and Chemical Research [Japon] (RIKEN), Instituto Geografico Nacional (IGN), National Astronomical Observatories [Beijing] (NAOC), Chinese Academy of Sciences [Beijing] (CAS), University College of London [London] (UCL), Spanish National Research Council (CSIC), Ural Federal University [Ekaterinburg] (UrFU), Departament de Química [Barcelona] (UAB), Universitat Autònoma de Barcelona (UAB), Institut de Physique de Rennes (IPR), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS), European Southern Observatory (ESO), Physique des interactions ioniques et moléculaires (PIIM), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Università degli studi di Torino (UNITO), IRAM PdBI/NOEMA Interferometer [V05B, V010, U003, L15AA], MPG (Germany)Max Planck Society, IGN (Spain), European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grantEuropean Union (EU) [664931], PRIN-INAF 2016 'The Cradle of Life -GENESIS-SKA (General Conditions in Early Planetary Systems for the rise of life with SKA)', European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programmeEuropean Research Council (ERC) [741002], European MARIE SKLODOWSKA-CURIE ACTIONS under the European Union's Horizon 2020 research and innovation programme [811312], French National Research Agency of the 'Origin of Life' project of the Universite Grenoble-AlpesFrench National Research Agency (ANR) [ANR-15-IDEX-02], INSU/CNRS (France)Centre National de la Recherche Scientifique (CNRS), Ceccarelli, C. [0000-0001-9664-6292], Balucani, N. [0000-0001-5121-5683], Rimola, A. [0000-0002-9637-4554], Al Edhari, A. J. [0000-0003-4089-841X], De Oliveira Alves, F. [0000-0002-7945-064X], Lefloch, B. [0000-0002-9397-3826], Persson, M. V. [0000-0002-1100-5734], Bachiller, R. [0000-0002-5331-5386], Pineda, J. [0000-0002-3972-1978], Segura Cox, D. [0000-0003-3172-6763], IRAM PdBI/NOEMA Interferometer, V05B V010 U003 L15AA, 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)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Météo-France -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)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Météo-France, Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique et Atmosphères = Laboratory for Studies of Radiation and Matter in Astrophysics and Atmospheres (LERMA), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-CY Cergy Paris Université (CY), 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 de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS), Università degli studi di Torino = University of Turin (UNITO), ANR-15-IDEX-0002,UGA,IDEX UGA(2015), Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737, Agence Nationale de la Recherche (ANR), European Research Council (ERC), 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)-CY Cergy Paris Université (CY), Taquet V., Codella C., De Simone M., Lopez-Sepulcre A., Pineda J.E., Segura-Cox D., Ceccarelli C., Caselli P., Gusdorf A., Persson M.V., Alves F., Caux E., Favre C., Fontani F., Neri R., Oya Y., Sakai N., Vastel C., Yamamoto S., Bachiller R., Balucani N., Bianchi E., Bizzocchi L., Chacon-Tanarro A., Dulieu F., Enrique-Romero J., Feng S., Holdship J., Lefloch B., Jaber Al-Edhari A., Jimenez-Serra I., Kahane C., Lattanzi V., Ospina-Zamudio J., Podio L., Punanova A., Rimola A., Sims I.R., Spezzano S., Testi L., Theule P., Ugliengo P., Vasyunin A.I., Vazart F., Viti S., and Witzel A.
Subjects: MILLIMETER ARRAYS, Binary number, CHEMICAL EVOLUTION, ISM: molecule, Astrophysics, Space (mathematics), 01 natural sciences, ISM: abundances, CHEMICAL CONDITIONS, ISM jets and outflows, ABUNDANCES [ISM], jets and outflows -ISM, CHEMICAL DIFFERENTIATION, 010303 astronomy & astrophysics, ISM abundances, Astrochemistry, Physics, [PHYS]Physics [physics], ASTROCHEMISTRY, Shock (fluid dynamics), INTERSTELLAR ICE, SUBMILLIMETRE TELESCOPES, NGC 1333-IRAS4A, ISM: abundance, ISM: molecules, stars formation, Radial velocity, ISM: jets and outflows, ISM individual objects NGC1333-IRAS4A, ISM: individual objects: NGC 1333-IRAS4A, CHEMICAL HISTORY, Low Mass, molecules -stars, Stars: formation, individual objects, JETS AND OUTFLOWS [ISM], FOS: Physical sciences, Context (language use), INDIVIDUAL OBJECTS: NGC 1333-IRAS4A [ISM], SILICON COMPOUNDS, SULFUR DIOXIDE, ISM molecules, astrochemistry -ISM, FORMATION [STARS], 0103 physical sciences, Protostar, ISM: jets and outflow, formation -ISM, 010308 nuclear & particles physics, Astronomy and Astrophysics, Astrophysics - Astrophysics of Galaxies, abundances -ISM, 13. Climate action, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), MOLECULES [ISM], Outflow, MOLECULAR OUTFLOWS, STARS
Abstract: Context. Low-mass protostars drive powerful molecular outflows that can be observed with millimetre and submillimetre telescopes. Various sulfuretted species are known to be bright in shocks and could be used to infer the physical and chemical conditions throughout the observed outflows. Aims. The evolution of sulfur chemistry is studied along the outflows driven by the NGC 1333-IRAS4A protobinary system located in the Perseus cloud to constrain the physical and chemical processes at work in shocks. Methods. We observed various transitions from OCS, CS, SO, and SO2 towards NGC 1333-IRAS4A in the 1.3, 2, and 3 mm bands using the IRAM NOrthern Extended Millimeter Array and we interpreted the observations through the use of the Paris-Durham shock model. Results. The targeted species clearly show different spatial emission along the two outflows driven by IRAS4A. OCS is brighter on small and large scales along the south outflow driven by IRAS4A1, whereas SO2 is detected rather along the outflow driven by IRAS4A2 that is extended along the north east-south west direction. SO is detected at extremely high radial velocity up to + 25 km s-1 relative to the source velocity, clearly allowing us to distinguish the two outflows on small scales. Column density ratio maps estimated from a rotational diagram analysis allowed us to confirm a clear gradient of the OCS/SO2 column density ratio between the IRAS4A1 and IRAS4A2 outflows. Analysis assuming non Local Thermodynamic Equilibrium of four SO2 transitions towards several SiO emission peaks suggests that the observed gas should be associated with densities higher than 105 cm-3 and relatively warm (T > 100 K) temperatures in most cases. Conclusions. The observed chemical differentiation between the two outflows of the IRAS4A system could be explained by a different chemical history. The outflow driven by IRAS4A1 is likely younger and more enriched in species initially formed in interstellar ices, such as OCS, and recently sputtered into the shock gas. In contrast, the longer and likely older outflow triggered by IRAS4A2 is more enriched in species that have a gas phase origin, such as SO2., With funding from the Spanish government through the "María de Maeztu Unit of Excellence" accreditation (MDM-2017-0737)
Published: 2020

13. The CARMA-NRO Orion Survey

Author: Adam Ginsburg, Paolo Padoan, Jens Kauffmann, Héctor G. Arce, Peter Schilke, Jaime E. Pineda, Rowan J. Smith, Shuo Kong, Ralf S. Klessen, Sümeyye Suri, Dariusz C. Lis, Paul F. Goldsmith, John M. Carpenter, Volker Ossenkopf-Okada, S. D. Clarke, Ana Duarte-Cabral, Steve Mairs, Doug Johnstone, John Bally, Álvaro Sánchez-Monge, Thushara Pillai, INAF - Osservatorio Astrofisico di Arcetri (OAA), Istituto Nazionale di Astrofisica (INAF), I. Physikalisches Institut [Köln], Universität zu Köln, Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), Center for Astrophysics and Space Astronomy [Boulder] (CASA), University of Colorado [Boulder], Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA (UMR_8112)), Sorbonne Université (SU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), School of Physics and Astronomy, and University of Manchester [Manchester]
Subjects: stars, individual objects, formation – ISM, ISM: structure, ISM: individual objects: Orion A, High resolution, FOS: Physical sciences, structure – ISM, Astrophysics, 01 natural sciences, ISM: clouds, Methods statistical, Protein filament, 0103 physical sciences, 010303 astronomy & astrophysics, Physics, methods: statistical, Line-of-sight, stars: formation, 010308 nuclear & particles physics, Star formation, Orion A – methods, Molecular cloud, Astronomy and Astrophysics, [PHYS.ASTR.SR]Physics [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], Astrophysics - Astrophysics of Galaxies, Stars, 13. Climate action, Space and Planetary Science, clouds – ISM, Astrophysics of Galaxies (astro-ph.GA), Substructure, statistical
Abstract: We present an initial overview of the filamentary structure in the Orion A molecular cloud utilizing a high angular and velocity resolution C$^{18}$O(1-0) emission map that was recently produced as part of the CARMA-NRO Orion Survey. The main goal of this study is to build a credible method to study varying widths of filaments which has previously been linked to star formation in molecular clouds. Due to the diverse star forming activities taking place throughout its $\sim$20 pc length, together with its proximity of 388 pc, the Orion A molecular cloud provides an excellent laboratory for such an experiment to be carried out with high resolution and high sensitivity. Using the widely-known structure identification algorithm, DisPerSE, on a 3-dimensional (PPV) C$^{18}$O cube, we identified 625 relatively short (the longest being 1.74 pc) filaments over the entire cloud. We study the distribution of filament widths using FilChaP, a python package that we have developed and made publicly available. We find that the filaments identified in a 2 square degree PPV cube do not overlap spatially, except for the complex OMC-4 region that shows distinct velocity components along the line of sight. The filament widths vary between 0.02 and 0.3 pc depending on the amount of substructure that a filament possesses. The more substructure a filament has, the larger is its width. We also find that despite this variation, the filament width shows no anticorrelation with the central column density which is in agreement with previous Herschel observations., Comment: 19 pages, 20 figures. Accepted for publication in Astronomy and Astrophysics
Published: 2019

14. Probing high-mass star formation in the outflow source G12.42+0.50

Author: Tej, Anandmayee
Subjects: jets, individual objects, Physics, HII regions, Multidisciplinary, Star formation, G12.42+0.50, Astrophysics, régions HII, jets and outflows, objets individuels, High mass, Outflow, (G12.42+0.50)
Abstract: This talk is based on the paper “Initial phases of high-mass star formation: A multiwavelength study towards the extended green object G12.42+0.50” by Namitha Issac, Anandmayee Tej, Tie Liu, Watson Varricatt, Sarita Vig, Ishwara Chandra CH and Mathias Schultheis and has been accepted for publication in MNRAS. A multiwavelength study of the extended green object G12.42+0.50 is presented. The associated ionized, dust, and molecular components of this source is probed using various observations at near- and far-infrared, submillimeter and radio wavelengths. The radio continuum emission mapped at 1390 and 610 MHz calls for a scenario of co-existence of an ultracompact (UC) H II region with an ionized jet possibly powered by the same young stellar object (YSO). Shock-excited lines of H2 and [Fe II] seen in the NIR spectra provide support to this picture. Study of the gas kinematics of the molecular cloud reveals the presence of both infall activity and large-scale molecular outflow, suggesting an early stage of massive star formation in G12.42+0.50.
Published: 2019
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15. Rotational spectroscopic study and astronomical search for propiolamide in Sgr B2(N)

Author: Elena R. Alonso, Jean-Claude Guillemin, Arnaud Belloche, Karl M. Menten, S. Mata, Robin T. Garrod, A. Jabri, Iker León, José L. Alonso, Holger S. P. Müller, Lucie Kolesniková, Ministerio de Economía y Competitividad (España), Ministerio de Ciencia, Innovación y Universidades (España), Agencia Estatal de Investigación (España), Czech Science Foundation, Junta de Castilla y León, European Research Council, European Commission, Fundación Biofísica Bizkaia, Centre National de la Recherche Scientifique (France), Centre National D'Etudes Spatiales (France), University of the Basque Country/Euskal Herriko Unibertsitatea (UPV/EHU), University of Chemistry and Technology Prague (UCT Prague), Max-Planck-Institut für Radioastronomie (MPIFR), Spanish National Research Council (CSIC), Universidad de Valladolid [Valladolid] (UVa), University of Virginia, Institut des Sciences Chimiques de Rennes (ISCR), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Universität zu Köln = University of Cologne, The funding from Ministerio de Ciencia e Innovación (CTQ2016-76393-P and PID2019-111396GB-I00), Czech Science Foundation (GACR, grant 19-25116Y), Junta de Castilla y León (Grants VA077U16 and VA244P20), and European Research Council under the European Union’s Seventh Framework Programme ERC-2013-SyG, Grant Agreement n. 610256 NANOCOSMOS are gratefully acknowledged. E.R.A. thanks Fundación Biofísica Bizkaia (FBB) for a postdoctoral contract. J.C.G. thanks the program Physique et Chimie du Milieu Interstellaire (INSU-CNRS) and the Centre National d’Etudes Spatiales (CNES). Part of this work has been carried out within the Collaborative Research Centre 956, sub-project B3, funded by the Deutsche Forschungsgemeinschaft (DFG) – project ID 184018867. R.T.G. acknowledges support from the National Science Foundation (grant No. AST 19-06489)., European Project: 610256,EC:FP7:ERC,ERC-2013-SyG,NANOCOSMOS(2014), University of Virginia [Charlottesville], Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA), and Universität zu Köln
Subjects: Astrochemistry, Line: identification, FOS: Physical sciences, Context (language use), Astrophysics, 01 natural sciences, Submillimeter Array, Article, Spectral line, Astronomical databases: miscellaneous, chemistry.chemical_compound, 0103 physical sciences, [CHIM]Chemical Sciences, Cyanoacetylene, 010303 astronomy & astrophysics, Hyperfine structure, Physics, 010304 chemical physics, Astronomy and Astrophysics, Astrophysics - Astrophysics of Galaxies, ISM: molecules, Sagittarius B2 – astronomical databases, Molecules – line, Individual objects, Miscellaneous, 3. Good health, chemistry, Astrochemistry – ISM, Identification – ISM, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), Excited state, Rotational spectroscopy, Astro-ph.GA, ISM: individual objects: Sagittarius B2
Abstract: For all the amides detected in the interstellar medium (ISM), the corresponding nitriles or isonitriles have also been detected in the ISM, some of which have relatively high abundances. Among the abundant nitriles for which the corresponding amide has not yet been detected is cyanoacetylene (HCCCN), whose amide counterpart is propiolamide (HCCC(O)NH2)., The funding from Ministerio de Ciencia e Innovación (CTQ2016-76393-P and PID2019-111396GB-I00), Czech Science Foundation (GACR, grant 19-25116Y), Junta de Castilla y León (Grants VA077U16 and VA244P20), and European Research Council under the European Union’s Seventh Framework Programme ERC-2013-SyG, Grant Agreement n. 610256 NANOCOSMOS are gratefully acknowledged. E.R.A. thanks Fundación Biofísica Bizkaia (FBB) for a postdoctoral contract. J.C.G. thanks the program Physique et Chimie du Milieu Interstellaire (INSU-CNRS) and the Centre National d’Etudes Spatiales (CNES).
Published: 2021

16. GALACTIC CENTER MINISPIRAL: INTERACTION MODES OF NEUTRON STARS

Author: Devaky Kunneriath, Michal Zajaček, and Vladimir Karas
Subjects: individual objects, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, neutron stars, Gravitation, Astrophysics::Galaxy Astrophysics, High Energy Astrophysical Phenomena (astro-ph.HE), Physics, Sagittarius A, Solar mass, Galactic Center, General Engineering, Astrophysics - Astrophysics of Galaxies, galaxy center, Galaxy, Stars, Neutron star, Star cluster, lcsh:TA1-2040, Astrophysics of Galaxies (astro-ph.GA), Astrophysics::Earth and Planetary Astrophysics, Astrophysics - High Energy Astrophysical Phenomena, lcsh:Engineering (General). Civil engineering (General)
Abstract: Streams of gas and dust in the inner parsec of the Galactic center form a distinct feature known as the Minispiral, which has been studied in radio waveband as well as in the infrared wavebands. A large fraction of the Minispiral gas is ionized by radiation of OB stars present in the Nuclear Star Cluster (NSC). Based on the inferred mass in the innermost parsec ($\sim 10^6$ solar masses), over $\sim 10^3$ -- $10^4$ neutron stars should move in the sphere of gravitational influence of the SMBH. We estimate that a fraction of them propagate through the denser, ionized medium concentrated mainly along the three arms of the Minispiral. Based on the properties of the gaseous medium, we discuss different interaction regimes of magnetised neutron stars passing through this region. Moreover, we sketch expected observational effects of these regimes. The simulation results may be applied to other galactic nuclei hosting NSC, where the expected distribution of the interaction regimes is different across different galaxy types., Comment: 12 pages, 17 figures, published in Acta Polytechnica
Published: 2015

17. History of the solar-type protostar IRAS 16293–2422 as told by the cyanopolyynes

Author: A. Jaber Al-Edhari, Emmanuel Caux, François Lique, Nadia Balucani, Alexandre Faure, D. Quénard, Claudine Kahane, Serena Viti, Laurent Wiesenfeld, E. Mendoza, Bertrand Lefloch, Cecilia Ceccarelli, Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), 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 Grenoble Alpes [2016-2019] (UGA [2016-2019])-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)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Università degli Studi di Perugia (UNIPG), Institut de recherche en astrophysique et planétologie (IRAP), Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Ondes et Milieux Complexes (LOMC), Centre National de la Recherche Scientifique (CNRS)-Université Le Havre Normandie (ULH), Normandie Université (NU)-Normandie Université (NU), Centro de Investigaciones Energéticas Medioambientales y Tecnológicas [Madrid] (CIEMAT), Centre National d'Études Spatiales [Toulouse] (CNES)-Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-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)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-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)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), Univ Toulouse UPS, Ctr Etud Spatiale Rayonnements, F-31062 Toulouse 9, France, Centre Etud Spatiale Rayonnements Toulouse, Neurobiologie de l'apprentissage, de la mémoire et de la communication (NAMC), Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS), Université Le Havre Normandie (ULH), Normandie Université (NU)-Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS), Centre Scientifique et Technique du Bâtiment (CSTB Saint Martin d'Hères), Centre Scientifique et Technique du Bâtiment (CSTB), Università degli Studi di Perugia = University of Perugia (UNIPG), 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), and 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)
Subjects: Astrochemistry, 010504 meteorology & atmospheric sciences, FOS: Physical sciences, Context (language use), Astrophysics, 01 natural sciences, Spectral line, IRAS 16293-2422, chemistry.chemical_compound, Abundances - ISM, 0103 physical sciences, Cyanoacetylene, Protostar, 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, Physics, [PHYS]Physics [physics], Cyanopolyyne, Molecular cloud, Astrochemistry - ISM, Individual objects, Astronomy and Astrophysics, Space and Planetary Science, Astrophysics - Astrophysics of Galaxies, Interstellar medium, chemistry, Astrophysics - Solar and Stellar Astrophysics, 13. Climate action, [SDU]Sciences of the Universe [physics], Astrophysics of Galaxies (astro-ph.GA)
Abstract: Cyanopolyynes are chains of carbon atoms with an atom of hydrogen and a CN group on either side. They are detected almost everywhere in the ISM, as well as in comets. In the past, they have been used to constrain the age of some molecular clouds, since their abundance is predicted to be a strong function of time. We present an extensive study of the cyanopolyynes distribution in the solar-type protostar IRAS16293-2422 based on TIMASSS IRAM-30m observations. The goals are (i) to obtain a census of the cyanopolyynes in this source and of their isotopologues; (ii) to derive how their abundance varies across the protostar envelope; and (iii) to obtain constraints on the history of IRAS16293-2422. We detect several lines from HC3N and HC5N, and report the first detection of DC3N, in a solar-type protostar. We found that the HC3N abundance is roughly constant (~1.3x10^(-11)) in the outer cold envelope of IRAS16293-2422, and it increases by about a factor 100 in the inner region where Tdust>80K. The HC5N has an abundance similar to HC3N in the outer envelope and about a factor of ten lower in the inner region. The HC3N abundance derived in the inner region, and where the increase occurs, also provide strong constraints on the time taken for the dust to warm up to 80K, which has to be shorter than ~10^3-10^4yr. Finally, the cyanoacetylene deuteration is about 50\% in the outer envelope and, Accepted for publication in A&A
Published: 2017

18. Image Mining Using Directional Spatial Constraints

Author: Ramazan Gokberk Cinbis and Selim Aksoy
Subjects: Morphology, Geographic information system, Image classification, Object detection, Comparative experiments, Spatial priors, Content model, Degree of satisfaction, Spatial relationships, computer.software_genre, Image mining, Image analysis, Geospatial intelligence, Reference objects, Dynamic Query, Electrical and Electronic Engineering, Spatial analysis, Image retrieval, Contextual classification, Contextual image classification, business.industry, Spatial database, Satellite imagery, Spatial relations, Geotechnical Engineering and Engineering Geology, Individual objects, In-buildings, Bayesian decision rule, Spatial relation, Spatial informations, Mathematical morphology, Spatial constraints, Retrieval performance, Data mining, business, computer, High resolution satellite imagery
Abstract: Spatial information plays a fundamental role in building high-level content models for supporting analysts' interpretations and automating geospatial intelligence. We describe a framework for modeling directional spatial relationships among objects and using this information for contextual classification and retrieval. The proposed model first identifies image areas that have a high degree of satisfaction of a spatial relation with respect to several reference objects. Then, this information is incorporated into the Bayesian decision rule as spatial priors for contextual classification. The model also supports dynamic queries by using directional relationships as spatial constraints to enable object detection based on the properties of individual objects as well as their spatial relationships to other objects. Comparative experiments using high-resolution satellite imagery illustrate the flexibility and effectiveness of the proposed framework in image mining with significant improvements in both classification and retrieval performance. © 2009 IEEE.
Published: 2010

19. A MUSE map of the central Orion Nebula (M 42)

Author: Roland Bacon, Christer Sandin, Andreas Kelz, Thomas P. K. Martinsson, Martin Wendt, Lutz Wisotzki, Adam Ginsburg, A. F. McLeod, Peter M. Weilbacher, Joseph Caruana, Johan Richard, Sebastian Kamann, Fernando Selman, Ana Monreal-Ibero, Arlette Pécontal-Rousset, Ralf Palsa, Jarle Brinchmann, Wolfram Kollatschny, Astrophysikalisches Institut Potsdam (AIP), Galaxies, Etoiles, Physique, Instrumentation (GEPI), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Institut für Astrophysik [Göttingen], Georg-August-University [Göttingen], European Southern Observatory (ESO), Centre de Recherche Astrophysique de Lyon (CRAL), École normale supérieure - Lyon (ENS Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), Leiden Observatory [Leiden], Universiteit Leiden [Leiden], Georg-August-University = Georg-August-Universität Göttingen, École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), and Universiteit Leiden
Subjects: Physics, Hii regions, individual objects, M 42, open clusters and associations, Trapezium cluster, Electron density, Field (physics), Extinction (astronomy), Institut für Physik und Astronomie, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, Astrophysics - Astrophysics of Galaxies, 01 natural sciences, Wavelength, [PHYS.ASTR.GA]Physics [physics]/Astrophysics [astro-ph]/Galactic Astrophysics [astro-ph.GA], Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), 0103 physical sciences, Orion Nebula, Electron temperature, Emission spectrum, 010306 general physics, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, Line (formation)
Abstract: We present a new integral-field spectroscopic dataset of the central part of the Orion Nebula (M 42), observed with the MUSE instrument at the ESO VLT. We reduced the data with the public MUSE pipeline. The output products are two FITS cubes with a spatial size of ~5.9'x4.9' (corresponding to ~0.76 pc x 0.63 pc) and a contiguous wavelength coverage of 4595...9366 Angstrom, spatially sampled at 0.2". We provide two versions with a sampling of 1.25 Angstrom and 0.85 Angstrom in dispersion direction. Together with variance cubes these files have a size of 75 and 110 GiB on disk. They represent one of the largest integral field mosaics to date in terms of information content. We make them available for use in the community. To validate this dataset, we compare world coordinates, reconstructed magnitudes, velocities, and absolute and relative emission line fluxes to the literature and find excellent agreement. We derive a two-dimensional map of extinction and present de-reddened flux maps of several individual emission lines and of diagnostic line ratios. We estimate physical properties of the Orion Nebula, using the emission line ratios [N II] and [S III] (for the electron temperature $T_e$) and [S II] and [Cl III] (for the electron density $N_e$), and show two-dimensional images of the velocity measured from several bright emission lines., Comment: Resubmitted to A&A after incorporating referee comments; access to full dataset via http://muse-vlt.eu/science/data-releases
Published: 2015

20. New results on the massive star-forming region S106 by BEAR spectro-imagery

Author: C. Joblin, Bernard Noël, T. Paumard, Jean-Pierre Maillard, Centre d'étude spatiale des rayonnements (CESR), 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), Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), and Université Fédérale Toulouse Midi-Pyrénées
Subjects: stars, formation -ISM, individual objects, Physics, interferometers -HII regionsastrochemistry, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Stellar mass, 010308 nuclear & particles physics, Star formation, Molecular cloud, Astronomy and Astrophysics, Astrophysics, 01 natural sciences, Sh 2-106 -instrumentation, Ion, [PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], Stars, 13. Climate action, Space and Planetary Science, Excited state, 0103 physical sciences, Emission spectrum, Spectral resolution, 010303 astronomy & astrophysics
Abstract: As a typical example of interaction of a massive star with its parent cloud, the close environment of S106 IR in the star-forming region S106 was observed at high spectral resolution (~16 km s -1 ). Integral field spectroscopy with BEAR, an imaging Fourier Transform Spectrometer (FTS), on a field of ~40´´in diameter, in the H 2 1–0 S (1), 2–1 S (1), Br γ , $\ion{He}{i}$ and [$\ion{Fe}{iii}$] lines. From the data several maps were obtained: intensity, velocity and linewidth in the Br γ and the H 2 1–0 S (1) line, 1–0 S (1)/2–1 S (1) line ratio, and continuum emission at 2.1 μ m. From the latter, about twenty low-mass stars were detected with photometry in this band, and an estimate of their mass was made leading to the conclusion that S106 is a site of formation of mainly sub-solar mass stars. The intensity structure of the excited molecular gas H 2 was found to be clumpy while the velocity is almost uniformely at $v_{{\rm LSR}}$ $\simeq$ 1.5 km s -1 except to the south where the velocity reaches up to 15 km s -1 in a zone limited by the long edge of a rectangular hole in the emission. The H 2 line ratio map with values from 1 to 9 implies that UV-absorption and shocks are participating in the excitation process. A PDR model with a temperature of 3700 K for S106 IR was used to retrieve the H 2 gas density and temperature. The density was found to vary between 1 and 3.5 $\times$ 10 5 cm -3 with corresponding temperatures between 660 and 1240 K. The study of the linewidth distribution indicates for most of the gas a supersonic turbulence with a mean contribution to the observed profiles of ≥ 6 km s -1 . Turbulence is likely to be responsible for the observed clumpy structure of the excited gas. Point-like spots with a linewidth as high as 30 km s -1 in one position are detected, which may be vortices in the molecular gas. The $\ion{H}{ii}$ region probed by Br γ shows a broad range of velocity, from -45 to +80 km s -1 , organized in velocity structures that correspond to two pairs of large, bipolar outflows originating from the massive source, not directed along the axis of the $\ion{H}{ii}$ region. Emission lines of $\ion{He}{i}$ and [$\ion{Fe}{iii}$] are detected in a bright area to the southwest of S106 IR, with point-like structures suggesting photoevaporating clumps. From the velocity data, a 3-D model of the environment of S106 IR is proposed. S106 is an example of an evolved $\ion{H}{ii}$ region seen face-on. The central source located at the edge of its parent molecular cloud has carved an expanding cylinder of turbulent, atomic gas of $\simeq$0.1 pc in radius. This massive object was formed by an accretion disk process. The disk is still present and the bipolar outflows are remnants of the massive star activity. A time scale of 1400 yr is estimated for the most recent event. A thin and quiescent clumpy layer of warm H 2 marks the transition of the $\ion{H}{ii}$ region to the molecular cloud. From the data, there are locally no signs of ongoing star formation.
Published: 2005

21. Overlapping Open Clusters NGC 1750 and NGC 1758 behind the Taurus Dark Clouds. II. CCD Photometry in the Vilnius System

Author: F. Smriglio, A. Cerniauskas, R. P. Boyle, V. Laugalys, A. G. Davis Philip, Algirdas Kazlauskas, K. Černis, V. Straižys, and F. J. Vrba
Subjects: individual objects, Astronomy, Extinction (astronomy), QB1-991, Astrophysics, Hubble sequence, Photometry (optics), symbols.namesake, photometric, vilnius photometric system stars, Stellar evolution, Physics, extinction, Astronomy and Astrophysics, dust clouds open clusters, Stars, Space and Planetary Science, ngc 1758, symbols, Spectrum analysis, techniques, classification ism, ngc 1750, Open cluster, fundamental parameters
Abstract: Seven-color photometry in the Vilnius system has been obtained for 420 stars down to V=16 mag in the area containing the overlapping open clusters NGC 1750 and NGC 1758 in Taurus. Spectral and luminosity classes, color excesses, interstellar extinctions, and interstellar distances are given for 287 stars. The classification of stars is based on their reddening-free Q-parameters. Eighteen stars observed photoelectrically were used as standards. The extinction versus distance diagram exhibits the presence of one dust cloud at a distance of 175 pc, which almost coincides with the distance of other dust clouds in the Taurus complex. The clusters NGC 1750 and NGC 1758 are found to be at the same distance of approximately 760 pc and may penetrate each other. Their interstellar extinction A(V) is 1.06 mag, which corresponds to E(B-V) = 0.34 mag. (3 tables, 5 figures, 10 refs.)
Published: 2003

22. Interstellar Extinction in the Direction of The Barnard 1 Dark Cloud in Perseus

Author: V. Straižys and K. Černis
Subjects: Physics, individual objects, business.industry, extinction, Astronomy, Interstellar cloud, Astronomy and Astrophysics, Cloud computing, QB1-991, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, photometric, Space and Planetary Science, Dark nebula, Astrophysics::Solar and Stellar Astrophysics, dust clouds ism, Astrophysics::Earth and Planetary Astrophysics, vilnius photometric system-stars, business, techniques, Astrophysics::Galaxy Astrophysics, classification ism, fundamental parameters, barnard 1
Abstract: Spectral and luminosity classes, absolute magnitudes, color excesses, interstellar extinctions and distances are determined for 98 stars down to 18 mag in the Barnard 1 dark cloud belonging to the Per OB2 association. The classification of stars is based on their photoelectric photometry in the Vilnius seven-color photometric system. The extinction vs. distance diagram exhibits the presence of two dust layers at 150 and 230 pc distances. The distance of the first cloud, which gives an extinction Ay of 0.3 mag, coincides with the distance of the Taurus dark cloud complex. The second cloud with much larger extinction is about at the same distance as the clouds in the direction of the nearby objects: reflection nebula NGC 1333 and open cluster IG 348.
Published: 2003

23. HESS J1640-465 - an exceptionally luminous TeV ${\gamma}$-ray supernova remnant

Author: G. Cologna, C. van Eldik, R. C. G. Chaves, S. Rosier-Lees, S. Raab, A. Abramowski, P. M. Chadwick, Felix Jankowsky, M. J. Vorster, Jacco Vink, Pierre-Olivier Petrucci, M. Renaud, Sabrina Casanova, Quirin Weitzel, A. Jacholkowska, D. Klochkov, L. O'c. Drury, S. Klepser, M. H. Grondin, Chia-Chun Lu, R. Chalme-Calvet, Christo Venter, G. Maurin, Michał Ostrowski, Tanya Edwards, C. Jahn, L. Rob, U. F. Katz, R. Moderski, A. Zech, Aion Viana, Francesca Volpe, A. A. Zdziarski, M. Dalton, D. Fernandez, G. Lamanna, B. Opitz, S. J. Nolan, Joachim Hahn, A. Wörnlein, Thomas Lohse, Markus Böttcher, C. Farnier, M. A. Kastendieck, A. Cheesebrough, Jan Conrad, Stefan Ohm, A. Fiasson, G. Vasileiadis, A. Djannati-Ataï, S. Pita, N. Maxted, Helen Poon, A. Lopatin, B. van Soelen, I. Jung, B. Rudak, Kathrin Egberts, D. Kolitzus, S. Schwarzburg, Martin Raue, F. Feinstein, B. Degrange, Michael Punch, J. Biteau, Guy Pelletier, A. Förster, T. Tavernier, B. Khélifi, G. Hermann, Regis Terrier, F. Schüssler, Mateusz Janiak, Anna Zajczyk, P. Wagner, Andrew M. Taylor, Stefan Wagner, Gisela Anton, M. Mayer, Frank M. Rieger, P.P. Krüger, T. Garrigoux, J. Dyks, R. D. Parsons, J.-P. Lenain, S. Häffner, Reinhard Schlickeiser, Pol Bordas, L. Oakes, I. D. Davids, Daniel Sánchez, Tomasz Bulik, Guillaume Dubus, Gianluca Giavitto, T. J. L. McComb, Hugh Dickinson, E. O. Angüner, Denis Wouters, Y. Cui, André Schulz, J. Méhault, G. Spengler, J. Brucker, H. Laffon, Dieter Horns, B. Peyaud, R. White, W. Kluźniak, W. Domainko, A. Balzer, Vincent Marandon, C. Couturier, S. Colafrancesco, J. Becker Tjus, T. Vuillaume, K. Dutson, F. Spies, G. Heinzelmann, J. Bolmont, P. J. Meintjes, Francois Brun, M. Chrétien, Jim Hinton, M. Grudzińska, N. W. Pekeur, Christoph Deil, Alexandre Marcowith, C. L. Naumann, T. Kneiske, P. deWilt, K. Katarzyński, Victor Zabalza, U. Menzler, Andreas Hillert, V. Sahakian, Andreas Quirrenbach, Michael Zacharias, Gavin Rowell, R. de los Reyes, Elisabetta Bissaldi, K. Stycz, J. F. Glicenstein, M. Holler, Łukasz Stawarz, Heinrich J. Völk, Gilles Henri, F. Stinzing, B. Giebels, S. J. Fegan, Svenja Carrigan, E. Birsin, Emmanuel Moulin, P. Espigat, Matteo Cerruti, F. Krayzel, Werner Hofmann, G. Fontaine, M. V. Fernandes, M. Gajdus, I. Oya, Jacek Niemiec, A. Lemière, Olaf Reimer, Ramin Marx, C. Trichard, Thomas Murach, P. Willmann, Michal Dyrda, M. de Naurois, Peter Eger, C. Stegmann, Nu. Komin, M. Panter, S. Krakau, P. Vincent, Martin Ward, Cameron B Rulten, S. Balenderan, E. de Oña Wilhelmi, C. Romoli, Konrad Bernlöhr, Felix Aharonian, K. Valerius, Julien Lefaucheur, Anna Barnacka, Matthias Weidinger, G. Pühlhofer, Dirk Lennarz, J. Perez, M. K. Daniel, A. Reimer, M. Kieffer, F. Ait Benkhali, S. Schwemmer, Andrea Santangelo, Yvonne Becherini, Anna Szostek, Petter Hofverberg, Iurii Sushch, M. Mohamed, Marianne Lemoine-Goumard, M. Füßling, J.-P. Tavernet, Manuel Meyer, Pierre Brun, M. Tluczykont, Y. A. Gallant, H.-S. Zechlin, O. Hervet, Catherine Boisson, Alicja Wierzcholska, S. Kaufmann, M. Paz Arribas, Ullrich Schwanke, A. G. Akhperjanian, R. Steenkamp, Marek Jamrozy, Helene Sol, J. Harris, Karl Kosack, H. E. S. S. Collaboration, Institut für Experimentalphysik [Hamburg], Universität Hamburg (UHH), Max Planck Institute for Nuclear Physics (MPIK), Max-Planck-Gesellschaft, National Academy of Sciences of the Republic of Armenia [Yerevan] (NAS RA), Yerevan Physics Institute, Yerevan State University, Humboldt-Universität zu Berlin, Physikalisches Institut [Erlangen], Friedrich-Alexander Universität Erlangen-Nürnberg (FAU), Department of Physics [Durham], University of New Hampshire (UNH), Deutsches Elektronen-Synchrotron [Zeuthen] (DESY), Helmholtz-Gemeinschaft = Helmholtz Association, Astronomical Observatory [Warsaw], Faculty of Physics [Warsaw] (FUW), University of Warsaw (UW)-University of Warsaw (UW), School of Computer Science, Physics and Mathematics [Linnaeus University], Linnaeus University, Institut für Theoretische Physik IV [Bochum] (ITP4), Ruhr-Universität Bochum [Bochum], Institut f¨ur Astro- und Teilchenphysik and Institut f¨ur Theoretische Physik, Leopold-Franzens Universitat Innsbruck, Laboratoire Leprince-Ringuet (LLR), Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), North-West University [South Aftrica] (NWU), Laboratoire Univers et Théories (LUTH (UMR_8102)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7), Laboratoire de Physique Nucléaire et de Hautes Énergies (LPNHE), Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Pierre et Marie Curie - Paris 6 (UPMC), Institut für Astronomie und Astrophysik [Tübingen] (IAAT), Eberhard Karls Universität Tübingen = Eberhard Karls University of Tuebingen, Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Astroparticules (ASTRO), Centre d'Etudes Nucléaires de Bordeaux Gradignan (CENBG), Université Sciences et Technologies - Bordeaux 1-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), APC - Astrophysique des Hautes Energies (APC - AHE), AstroParticule et Cosmologie (APC (UMR_7164)), Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Dipartimento di Astronomia, Universita degli Studi di Bologna, Alma Mater Studiorum Università di Bologna [Bologna] (UNIBO)-Alma Mater Studiorum Università di Bologna [Bologna] (UNIBO), Dublin Institute for Advanced Studies (DIAS), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Laboratoire Univers et Particules de Montpellier (LUPM), Université Montpellier 2 - Sciences et Techniques (UM2)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Annecy de Physique des Particules (LAPP), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Universität Potsdam, Department of Physics [Durham University], Durham University, HESS, Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Dipartimento di Astronomia, Universita degli Studi di Bologna, Università di Bologna [Bologna] (UNIBO)-Università di Bologna [Bologna] (UNIBO), PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7), Université de Montpellier (UM)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Annecy de Physique des Particules (LAPP/Laboratoire d'Annecy-le-Vieux de Physique des Particules), High Energy Astrophys. & Astropart. Phys (API, FNWI), Humboldt University Of Berlin, Universität Innsbruck [Innsbruck], Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1 (UB)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Alma Mater Studiorum Università di Bologna [Bologna] (UNIBO), Université Montpellier 2 - Sciences et Techniques (UM2)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), and University of Potsdam = Universität Potsdam
Subjects: [PHYS.ASTR.HE]Physics [physics]/Astrophysics [astro-ph]/High Energy Astrophysical Phenomena [astro-ph.HE], Photon, Radiation mechanisms: non-thermal, Supernova remnants, Astrophysics::High Energy Astrophysical Phenomena, Hadron, Hochenergie-Astrophysik Theorie - Abteilung Hofmann, FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 7. Clean energy, 01 natural sciences, Power law, Spectral line, ISM: individual objects: G338.3−0.0, G338.3-0.0-ISM, Individual objects, Non-thermal-ISM, Radiation mechanisms, Astronomy and Astrophysics, Space and Planetary Science, 0103 physical sciences, High Energy Stereoscopic System, Supernova remnant, 010303 astronomy & astrophysics, HESS - Abteilung Hofmann, ISM: supernova remnant, High Energy Astrophysical Phenomena, Astroparticle physics, Physics, High Energy Astrophysical Phenomena (astro-ph.HE), non-thermal [Radiation mechanisms], 010308 nuclear & particles physics, supernova remnants [ISM], [SDU.ASTR.HE]Sciences of the Universe [physics]/Astrophysics [astro-ph]/High Energy Astrophysical Phenomena [astro-ph.HE], Institut für Physik und Astronomie, Astronomy, individual objects: G338.3−0.0 [ISM], Supernova, supernova remnants. [ISM], ddc:520, High Energy Physics::Experiment, Astrophysics - High Energy Astrophysical Phenomena
Abstract: The results of follow-up observations of the TeV gamma-ray source HESSJ 1640-465 from 2004 to 2011 with the High Energy Stereoscopic System (H.E.S.S.) are reported in this work. The spectrum is well described by an exponential cut-off power law with photon index Gamma=2.11 +/- 0.09_stat +/- 0.10_sys, and a cut-off energy of E_c = (6.0 +2.0 -1.2) TeV. The TeV emission is significantly extended and overlaps with the north-western part of the shell of the SNR G338.3-0.0. The new H.E.S.S. results, a re-analysis of archival XMM-Newton data, and multi-wavelength observations suggest that a significant part of the gamma-ray emission from HESS J1640-465 originates in the SNR shell. In a hadronic scenario, as suggested by the smooth connection of the GeV and TeV spectra, the product of total proton energy and mean target density could be as high as W_p n_H ~ 4 x 10^52 (d/10kpc)^2 erg cm^-3., accepted for publication in MNRAS, 9 pages, 5 figures, added Spitzer citation and acknowledgement
Published: 2014

24. Dynamic modeling of an integrated air-to-air heat pump using Modelica

Author: Assaad Zoughaib, Sorina Mortada, Denis Clodic, Christine Arzano-Daurelle, CEP/Paris, Centre Énergétique et Procédés (CEP), MINES ParisTech - École nationale supérieure des mines de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-MINES ParisTech - École nationale supérieure des mines de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Energie dans les Bâtiments et les Territoires (EDF R&D ENERBAT), EDF R&D (EDF R&D), and EDF (EDF)-EDF (EDF)
Subjects: Modelica, Heat pump systems, Computer science, 020209 energy, 02 engineering and technology, 01 natural sciences, Air temperature, System response, law.invention, law, Models, Component (UML), Air source heat pumps, 0202 electrical engineering, electronic engineering, information engineering, Air mass flow rate, Predictive control, Thermodynamic systems, Experimentation, Competition, Control strategies, Mechanical Engineering, Market share, Control engineering, Building and Construction, Fast systems, Object-oriented modeling, Thermodynamic system, 010406 physical chemistry, 0104 chemical sciences, System dynamics, Individual objects, [SPI.TRON]Engineering Sciences [physics]/Electronics, Model predictive control, External perturbations, Current (fluid), Physical behaviors, Heat pump, Dynamic modeling
Abstract: International audience; Heat pump systems have gained significant market shares in Europe recently. The control strategy is an asset for the efficient operation of these thermodynamic systems; especially with compact integrated components. The predictive control, which allows fast system stabilization, is based on the description of the system physical behavior. Thus, dynamic modeling is needed for the development of such control. The model has to represent the system response to usual external perturbations met during current operation such as the variation of air temperature and air mass flow rate. The aim of this paper is to present a dynamic model of a thermodynamic system developed in the Dymola environment, which is an object-oriented modeling environment. The heat-pump components are created separately as individual objects, and then connected to form the system. The model of each component is described and the responses to different perturbations are detailed. Simulation results are compared to test results in order to validate the model.
Published: 2012

25. Detection of compound structures using clustering of statistical and structural features

Author: H. Gokhan Akcay and Selim Aksoy
Subjects: Signal processing, Compound structures, Structural characteristics, Computer science, Feature extraction, Graph vertex, Hier-archical clustering, Edge detection, Object groups, Position data, Position (vector), Structural information, Cluster analysis, business.industry, Pattern recognition, Image segmentation, Traditional techniques, Object (computer science), Graph, Individual objects, Vertex (geometry), Hierarchical clustering, Graph theory, Spatial alignment, Statistical information, Graph (abstract data type), Artificial intelligence, business, Structural feature
Abstract: Date of Conference: 18-20 April 2012 We describe a new method for detecting compound structures in images by combining the statistical and structural characteristics of simple primitive objects. A graph is constructed by assigning the primitive objects to its vertices, and connecting potentially related objects using edges. Statistical information that is modeled using spectral, shape, and position data of individual objects as well as the structural information that is modeled in terms of spatial alignments of neighboring object groups are also encoded in this graph. Experiments using WorldView-2 data show that hierarchical clustering of the graph vertices can discover high-level compound structures that cannot be obtained using traditional techniques. © 2012 IEEE.
Published: 2012

26. The Herschel view of the on-going star formation in the Vela-C molecular cloud

Author: D. Lorenzetti, D. Polychroni, Sylvain Bontemps, Milena Benedettini, Davide Elia, Kazi L.J. Rygl, Ph. André, G. J. White, Sergio Molinari, J. Di Francesco, Nicola Schneider, T. Hill, T. Giannini, Jason M. Kirk, Derek Ward-Thompson, Vincent Minier, Cassandra Fallscheer, L. Spinoglio, A. Di Giorgio, Stefano Pezzuto, M. R. Pestalozzi, Q. Nguyen Luong, E. Schisano, Frédérique Motte, Paolo Saraceno, Leonardo Testi, Martin Hennemann, foreign laboratories (FL), CERN [Genève], INAF - Osservatorio Astronomico di Roma (OAR), Istituto Nazionale di Astrofisica (INAF), Istituto di Fisica dello Spazio Interplanetario (IFSI), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), 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), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Institut de Planétologie et d'Astrophysique de Grenoble (IPAG ), Observatoire des Sciences de l'Univers de Grenoble (OSUG), 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), FORMATION STELLAIRE 2012, Laboratoire d'astrodynamique, d'astrophysique et d'aéronomie de bordeaux (L3AB), 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 de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Bordeaux (UB), Herzberg Institute of Astrophysics, National Research Council of Canada (NRC), Antarctic Research a European Network for Astrophysics (ARENA), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), European Southern Observatory (ESO), School of Physics and Astronomy [Cardiff], Cardiff University, Engineering Department, University of Cambridge [UK] (CAM), Osservatorio di Astrofisica di Roma (OAR), Consiglio Nazionale delle Ricerche (CNR), 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), 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), 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), and 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)
Subjects: individual objects, stars, FOS: Physical sciences, Astrophysics, clouds, Astrophysics::Cosmology and Extragalactic Astrophysics, Vela, 01 natural sciences, Power law, circumstellar matter, Virial theorem, 0103 physical sciences, Protostar, Astrophysics::Solar and Stellar Astrophysics, submillimeter, Vela-C, 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics::Galaxy Astrophysics, QB, Physics, Mass distribution, 010308 nuclear & particles physics, Star formation, [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], Molecular cloud, formation, Astronomy and Astrophysics, Galactic plane, [PHYS.ASTR.SR]Physics [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science
Abstract: As part of the Herschel guaranteed time key program 'HOBYS', we present the photometric survey of the star forming region Vela-C, one of the nearest sites of low-to-high-mass star formation in the Galactic plane. Vela-C has been observed with PACS and SPIRE in parallel mode between 70 um and 500 um over an area of about 3 square degrees. A photometric catalogue has been extracted from the detections in each band, using a threshold of 5 sigma over the local background. Out of this catalogue we have selected a robust sub-sample of 268 sources, of which 75% are cloud clumps and 25% are cores. Their Spectral Energy Distributions (SEDs) have been fitted with a modified black body function. We classify 48 sources as protostellar and 218 as starless. For two further sources, we do not provide a secure classification, but suggest they are Class 0 protostars. From SED fitting we have derived key physical parameters. Protostellar sources are in general warmer and more compact than starless sources. Both these evidences can be ascribed to the presence of an internal source(s) of moderate heating, which also causes a temperature gradient and hence a more peaked intensity distribution. Moreover, the reduced dimensions of protostellar sources may indicate that they will not fragment further. A virial analysis of the starless sources gives an upper limit of 90% for the sources gravitationally bound and therefore prestellar. We fit a power law N(logM) prop M^-1.1 to the linear portion of the mass distribution of prestellar sources. This is in between that typical of CO clumps and those of cores in nearby star-forming regions. We interpret this as a result of the inhomogeneity of our sample, which is composed of comparable fractions of clumps and cores., 9 pages, 7 figures, accepted by A&A
Published: 2012

27. Detection of compound structures using hierarchical clustering of statistical and structural features

Author: H. Gokhan Akcay and Selim Aksoy
Subjects: Compound structures, Structural characteristics, Object detection, Feature extraction, Hier-archical clustering, Object groups, Position data, alignment detection, Structural information, Alignment, Mathematics, Pattern clustering, business.industry, Geology, Pattern recognition, Graph theory, Image segmentation, Remote sensing, Traditional techniques, graph-based representation, Individual objects, Hierarchical clustering, Graph-based representations, Spatial alignment, Statistical information, Graph (abstract data type), Artificial intelligence, business, hierarchical clustering, Graph structures, Structural feature
Abstract: Date of Conference: 24-29 July 2011 We describe a new procedure that combines statistical and structural characteristics of simple primitive objects to discover compound structures in images. The statistical information that is modeled using spectral, shape, and position data of individual objects, and structural information that is modeled in terms of spatial alignments of neighboring object groups are encoded in a graph structure that contains the primitive objects at its vertices, and the edges connect the potentially related objects. Experiments using WorldView-2 data show that hierarchical clustering of these vertices can find high-level compound structures that cannot be obtained using traditional techniques. © 2011 IEEE.
Published: 2011

28. Oxygen depletion in dense molecular clouds: a clue to a low O2 abundance?

Author: Jean-Christophe Loison, Stéphane Guilloteau, Jürgen Troe, Pascal Honvault, Franck Hersant, U. Hincelin, Valentine Wakelam, 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), 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), Université Sciences et Technologies - Bordeaux 1, Laboratoire d'astrodynamique, d'astrophysique et d'aéronomie de bordeaux (L3AB), Univers, Transport, Interfaces, Nanostructures, Atmosphère et environnement, Molécules (UMR 6213) (UTINAM), Université de Franche-Comté (UFC), Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), Institute of Physical Chemistry, Georg-August-University [Göttingen], aMOR 2011, 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), and FORMATION STELLAIRE 2011
Subjects: Astrochemistry, Chemical models, [SDU.ASTR.CO]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], Analytical chemistry, chemistry.chemical_element, FOS: Physical sciences, Astrophysics, Kinetic energy, 01 natural sciences, Oxygen, [PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], 0103 physical sciences, Solar and Stellar Astrophysics, 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics::Galaxy Astrophysics, Physics, 010304 chemical physics, [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], Molecular cloud, Astronomy and Astrophysics, astrochemistry, ISM, abundances, molecules, individual objects, L134N, TMC-1, [PHYS.ASTR.SR]Physics [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], Nitrogen, chemistry, Astrophysics - Solar and Stellar Astrophysics, 13. Climate action, Space and Planetary Science, Molecular oxygen, Chemical network
Abstract: Context: Dark cloud chemical models usually predict large amounts of O2, often above observational limits. Aims: We investigate the reason for this discrepancy from a theoretical point of view, inspired by the studies of Jenkins and Whittet on oxygen depletion. Methods: We use the gas-grain code Nautilus with an up-to-date gas-phase network to study the sensitivity of the molecular oxygen abundance to the oxygen elemental abundance. We use the rate coefficient for the reaction O + OH at 10 K recommended by the KIDA (KInetic Database for Astrochemistry) experts. Results: The updates of rate coefficients and branching ratios of the reactions of our gas-phase chemical network, especially N + CN and H3+ + O, have changed the model sensitivity to the oxygen elemental abundance. In addition, the gas-phase abundances calculated with our gas-grain model are less sensitive to the elemental C/O ratio than those computed with a pure gas-phase model. The grain surface chemistry plays the role of a buffer absorbing most of the extra carbon. Finally, to reproduce the low abundance of molecular oxygen observed in dark clouds at all times, we need an oxygen elemental abundance smaller than 1.6E-4. Conclusion: The chemistry of molecular oxygen in dense clouds is quite sensitive to model parameters that are not necessarily well constrained. That O2 abundance may be sensitive to nitrogen chemistry is an indication of the complexity of interstellar chemistry., 6 pages, 3 figures, accepted for publication in Astronomy & Astrophysics
Published: 2011

29. SEARCH FOR THE 1.67 MU-M PAH EMISSION BAND - MORE UPPER LIMITS

Subjects: PLANETARY NEBULAE, HE-2-77, CONTINUUM EMISSION, INTERSTELLAR MEDIUM, INDIVIDUAL, SPECTROSCOPY, IRAS SOURCES, RED RECTANGLE, INFRARED-EMISSION, FEATURES, DUST, INDIVIDUAL OBJECTS, ORION BAR, POLYCYCLIC AROMATIC-HYDROCARBONS, CARBON, EXTINCTION, SPECTRA, NEBULAE, INTERSTELLAR DUST
Abstract: In an attempt to further resolve the origin and excitation mechanism of the unidentified infrared emission bands, we have obtained high resolution spectroscopy in the H-band for three objects with strong 3.28 and 3.4 mu m emission features. In the scenario of highly vibrational excited, isolated, polycyclic aromatic hydrocarbons a broad band resonance at about 1.67 mu m with an intensity of I-3.4/I-1.67 less than or equal to 6 has been predicted, that should be detectable for our three objects: the Orion bar at position 4, He2-77 and the Red Rectangle. However, this prediction has not been confirmed by us. Our upper limits show that the intensity of the second harmonic should be at least 48 times weaker than the intensity of the 3.4 mu m C-H stretching mode. We conclude that both the hot band theory and the explanation that the excitation of the 3.4 mu m feature is due to molecular side groups is questionable. More laboratory data such as measurements of the first overtone emission of PAH structures like cyclopropylidene (C3H2) and phenanthereneare (C10H14) are needed.
Published: 1993

30. Object detection with contextual inference

Author: Kalaycılar, Fırat and Aksoy, Selim
Subjects: Optimization, Signal processing, Real-world objects, Object detection, Probability functions, Textual information, Linear optimization, Object detection systems, Spatial relationships, Individual objects, Maximization problem, Detection performance, Data sets, 2D images, Signal detection
Abstract: Date of Conference: 9-11 April 2009 Conference name: IEEE 17th Signal Processing and Communications Applications Conference, 2009 Bu bildiride, sezim başarımını arttırmada tek tek sezilmiş nesneler arasındaki bağlamsal ilişkilerden yararlanan bir nesne sezim sistemi tanıtılmaktadır. Bu çalışmadaki ilk katkı, iki boyutlu görüntü uzayında yapılan ölçümlerden olasılıksal çıkarım yaparak nesneler arası gerçek dünya ilişkilerinin (çevresinde, yakınında, üzerinde vb.) modellenmesidir. Diğer bir katkı ise, bireysel nesne etiketlerine ve nesne ikilileri arasındaki ilişkilere bağlı olan sahne olasılık fonksiyonunun enbüyütülerek, nesnelerin en son etiketlerinin atanmasıdır. En tutarlı sahne duzenleşimini bulmak için bu enbüyütme problemi, doğrusal eniyileme kullanılarak çözülmüştür. Ofis görüntüleri içeren iki farklı veri kümesinde yapılan deneylerde, gerçek dünya uzamsal ilişkileri bağlamsal bilgi olarak kullanıldığında genel sezim başarımının arttığı gözlemlenmiştir. In this paper, an object detection system that utilizes contextual relationships between individually detected objects to improve the overall detection performance is introduced. The first contribution in this work is the modelling of real world object relationships (beside, on, near etc.) that can be probabilistically inferred using measurements in the 2D image space. The other contribution is the assignment offinol lobe/s to the detected objects by maximizing a scene probability function that is defined jointly using both individual object labels and their pairwise spatial relationships. The most consistent scene configuration is obtained by solving the maximization problem using linear optimization. Experiments on two different office data sets showed that incorporation of the real world spatial relationships as can textual information improved the overall detection performance. ©2009 IEEE.
Published: 2009

31. OH and H2O maser variations in W33B

Author: Chiappini, C., Anders, F., Rodrigues, T., Miglio, A., Montalban, J., Mosser, B., Girardi, L., Valentini, M., Noels, A., Morel, T., Minchev, I., Steinmetz, M., Santiago, B., Schultheis, M., Martig, M., da Costa, L., Maia, M., Allende Prieto, C., de Assis Peralta, R., Hekker, S., Themessl, N., Kallinger, T., Garcia, R., Mathur, S., Baudin, F., Beers, T., Cunha, K., Harding, P., Holtzman, J., Majewski, S., Mészáros, Sz., Nidever, D., Pan, K., Schiavon, R., Shetrone, M., Schneider, D., Stassun, K., Colom, P., Lekht, E., Pashchenko, M., Rudnitskij, G., Leibniz-Institut für Astrophysik Potsdam (AIP), Institut d'Astrophysique et de Géophysique [Liège], Université de Liège, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), 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 Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), INAF - Osservatorio Astronomico di Padova (OAPD), Istituto Nazionale di Astrofisica (INAF), Département d'astrophysique, Géophysique et Océanographie (AGO), Joseph Louis LAGRANGE (LAGRANGE), Université Nice Sophia Antipolis (1965 - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), Liverpool John Moores University (LJMU), Laboratoire Géosciences Océan (LGO), Université de Bretagne Sud (UBS)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS), Mullard Space Science Laboratory (MSSL), University College of London [London] (UCL), School of Physics and Astronomy, University of Birmingham [Birmingham], Institute for Astronomy [Vienna], University of Vienna [Vienna], Institut de Physique du Globe de Paris (IPG Paris), Space Science Institute [Boulder] (SSI), Commissariat à l'énergie atomique et aux énergies alternatives - Laboratoire d'Electronique et de Technologie de l'Information (CEA-LETI), Direction de Recherche Technologique (CEA) (DRT (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Center for the Study of Cosmic Evolution (CSCE), Michigan State University [East Lansing], Michigan State University System-Michigan State University System, Department of Geography, Department of geography, Université Nice Sophia Antipolis (... - 2019) (UNS), Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), Institut Français de Recherche pour l'Exploitation de la Mer - Brest (IFREMER Centre de Bretagne), Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Bretagne Sud (UBS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS), Institut de Physique du Globe de Paris, Université Côte d'Azur (UCA)-Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Observatoire de la Côte d'Azur, Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Université de Bretagne Sud (UBS)-Université de Brest (UBO)-Institut Universitaire Européen de la Mer (IUEM), and Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)
Subjects: individual objects, 85A15, lines and bands -ISM, Astrophysics::High Energy Astrophysical Phenomena, Central object, FOS: Physical sciences, Astrophysics, 01 natural sciences, W33B, law.invention, Radio telescope, symbols.namesake, law, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, Maser, masers -ISM, 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics::Galaxy Astrophysics, magnetic fields -ISM, Line (formation), [PHYS]Physics [physics], Physics, Zeeman effect, 010308 nuclear & particles physics, molecules -ISM, Astronomy and Astrophysics, Astrophysics - Astrophysics of Galaxies, Magnetic field, Wavelength, Astrophysics - Solar and Stellar Astrophysics, 13. Climate action, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), symbols, Astrophysics::Earth and Planetary Astrophysics, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Excitation
Abstract: The active star-forming region W33B is a source of OH and H2O maser emission located in distinct zones around the central object. The aim was to obtain the complete Stokes pattern of polarised OH maser emission, to trace its variability and to investigate flares and long-term variability of the H2O maser and evolution of individual emission features. Observations in the OH lines at a wavelength of 18 cm were carried out on the Nan\c{c}ay radio telescope (France) at a number of epochs in 2008--2014; H2O line observations (long-term monitoring) at a wavelength of 1.35 cm were performed on the 22-metre radio telescope of the Pushchino Radio Astronomy Observatory (Russia) between 1981 and 2014. We have observed strong variability of the emission features in the main 1665- and 1667-MHz OH lines as well as in the 1612-MHz satellite line. Zeeman splitting has been detected in the 1665-MHz OH line at 62 km/s and in the 1667-MHz line at 62 and 64 km/s. The magnetic field intensity was estimated to be from 2 to 3 mG. The H2O emission features form filaments, chains with radial-velocity gradients, or more complicated structures including large-scale ones. Long-term observations of the hydroxyl maser in the W33B region have revealed narrowband polarised emission in the 1612-MHz line with a double-peak profile characteristic of Type IIb circumstellar masers. The 30-year monitoring of the water-vapour maser in W33B showed several strong flares of the H2O line. The observed radial-velocity drift of the H2O emission features suggests propagation of an excitation wave in the masering medium with a gradient of radial velocities. In OH and H2O masers some turbulent motions of material are inferred., Comment: 18 pages, 12 figures
Published: 2015

32. Velocity field and star formation in the Horsehead nebula

Author: Rolf Güsten, Sabin Philipp, Pierre Hily-Blant, D. Teyssier, 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), Institut de RadioAstronomie Millimétrique (IRAM), Centre National de la Recherche Scientifique (CNRS), SRON Netherlands Institute for Space Research (SRON), and Max-Planck-Institut für Radioastronomie (MPIFR)
Subjects: individual objects, 010504 meteorology & atmospheric sciences, Continuum (design consultancy), kinematics and dynamics, individual objects (Horsehead nebula), FOS: Physical sciences, Angular velocity, Astrophysics, ISM: clouds, 01 natural sciences, Horsehead nebula -stars, [PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], Protein filament, clouds -ISM, 0103 physical sciences, Differential rotation, 010303 astronomy & astrophysics, Radio lines: ISM, ISM, 0105 earth and related environmental sciences, Physics, Nebula, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Star formation, Velocity gradient, Astrophysics (astro-ph), kinematics and dynamics -ISM, Astronomy and Astrophysics, Ridge (differential geometry), [SDU]Sciences of the Universe [physics], 13. Climate action, Space and Planetary Science, formationradio lines, Stars: Formation
Abstract: Using large scale maps in C18O(2-1) and in the continuum at 1.2mm obtained at the IRAM-30m antenna with the Heterodyne Receiver Array (HERA) and MAMBO2, we investigated the morphology and the velocity field probed in the inner layers of the Horsehead nebula. The data reveal a non--self-gravitating (m/mvir = 0.3) filament of dust and gas (the "neck", diameter = 0.15-0.30 pc) connecting the Horsehead western ridge, a Photon-Dominated Region illuminated by sigmaOri, to its parental cloud L1630. Several dense cores are embedded in the ridge and the neck. One of these cores appears particularly peaked in the 1.2 mm continuum map and corresponds to a feature seen in absorption on ISO maps around 7 micr. Its \cdo emission drops at the continuum peak, suggestive of molecular depletion onto cold grains. The channel maps of the Horsehead exhibit an overall north-east velocity gradient whose orientation swivels east-west, showing a somewhat more complex structure than was recently reported by \cite{pound03} using BIMA CO(1-0) mapping. In both the neck and the western ridge, the material is rotating around an axis extending from the PDR to L1630 (angular velocity=1.5-4.0 km/s). Moreover, velocity gradients along the filament appear to change sign regularly (3 km/s/pc, period=0.30 pc) at the locations of embedded integrated intensity peaks. The nodes of this oscillation are at the same velocity. Similar transverse cuts across the filament show a sharp variation of the angular velocity in the area of the main dense core. The data also suggest that differential rotation is occurring in parts of the filament. We present a new scenario for the formation and evolution of the nebula and discuss dense core formation inside the filament., 11 pages, 9 figures, A&A
Published: 2006

33. Far-Infrared detection of methylene

Author: S. Bruenken, J.-P. Baluteau, Gisbert Winnewisser, Karl M. Menten, E. T. Polehampton, 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), and 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)
Subjects: individual objects, molecular data, Analytical chemistry, FOS: Physical sciences, Astrophysics, 01 natural sciences, [PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], chemistry.chemical_compound, Far infrared, 0103 physical sciences, W49, Molecule, Sagittarius B2, Methylene, 010306 general physics, Absorption (electromagnetic radiation), 010303 astronomy & astrophysics, Physics, infrared: ISM, Spectrometer, Molecular cloud, Astrophysics (astro-ph), Sagittarius B2 -ISM, Astronomy and Astrophysics, molecules -molecular data -ISM, ISM: molecules, Interstellar medium, chemistry, 13. Climate action, Space and Planetary Science, ISM: individual objects: W49, ISM -ISM, infrared, ISM: individual objects: Sagittarius B2
Abstract: We present a clear detection of CH2 in absorption towards the molecular cloud complexes Sagittarius B2 and W49 N using the ISO Long Wavelength Spectrometer. These observations represent the first detection of its low excitation rotational lines in the interstellar medium. Towards Sagittarius B2, we detect both ortho and para transitions allowing a determination of the total CH2 column density of N(CH2)=(7.5+/-1.1)x10^14 cm^-2. We compare this with the related molecule, CH, to determine [CH/CH2]=2.7+/-0.5. Comparison with chemical models shows that the CH abundance along the line of sight is consistent with diffuse cloud conditions and that the high [CH/CH2] ratio can be explained by including the effect of grain-surface reactions., Comment: 11 pages, 4 figures, accepted for publication in A&A
Published: 2005

34. Shock-induced PDR in the Herbig-Haro object HH2

Author: S. Cabrit, D. Cesarsky, José Cernicharo, Bertrand Lefloch, 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), Centro de Investigaciones Biológicas (CSIC), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA), École normale supérieure - Paris (ENS Paris), 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), Max-Planck-Institut für Extraterrestrische Physik (MPE), Le Floch, Bertrand, and École normale supérieure - Paris (ENS-PSL)
Subjects: individual objects, Astrophysics::High Energy Astrophysical Phenomena, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, [PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, Herbig–Haro object, jets and outflows -ISM, Basso continuo, 010303 astronomy & astrophysics, ISM, HH 1/2 -ISM, Astrophysics::Galaxy Astrophysics, Physics, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], 010308 nuclear & particles physics, Star formation, Molecular cloud, formation, HH objects, Astronomy, Astronomy and Astrophysics, Herbig-Haro objects -ISM, jets and outflows, Space and Planetary Science, [PHYS.ASTR.CO] Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], [SDU]Sciences of the Universe [physics], extinctionstars, Millimeter, Outflow, Astrophysics::Earth and Planetary Astrophysics, dust, Excitation
Abstract: International audience; We report mid-infrared (5{-}17 μ m) and SO, CO, {13CO} millimeter line observations of the protostellar jet HH 2 and the parental molecular cloud. We have detected for the first time mid-infrared emission along a protostellar jet. We find that the outflowing gas extends much further away than the Herbig-Haro object HH 2, showing direct evidence that downstream gas has been accelerated by previous outflow events. These gas layers appear to have been detached from the parental cloud, as they are distributed around a cavity, probably dug by protostellar outflow(s). SO emission is detected in shocked gas regions associated with outflows. The UV field produced in the strong shock region HH 2H-A has produced a low-excitation Photon-Dominated Region at the walls of the cavity, which is detected in the PAH emission bands and in the continuum between 5 and 17 μ m. This continuum arises from very small grains transiently heated by a FUV field G ≃ 20 G_0, which probably formed from evaporation of dust grain mantles in shocks.
Published: 2004

35. Sequential star formation at the periphery of the HII regions Sh 217 and Sh 219

Author: Luis Salas, Annie Zavagno, Irene Cruz-González, Lise Deharveng, A. Porras, J. Caplan, 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), Institut de Biologie du Développement de Marseille (IBDM), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), and 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)
Subjects: individual objects, H II region, Strömgren sphere, 010504 meteorology & atmospheric sciences, Continuum (design consultancy), FOS: Physical sciences, Astrophysics, Photodissociation region, 01 natural sciences, Ionization, 0103 physical sciences, Cluster (physics), Sh 219 -stars, formationstars, early-type, 010303 astronomy & astrophysics, ISM, 0105 earth and related environmental sciences, Physics, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Star formation, Astrophysics (astro-ph), Astronomy and Astrophysics, Ionization front, 13. Climate action, Space and Planetary Science, H  regions -ISM, Sh 217 -ISM
Abstract: The HII regions Sh 217 and Sh 219 are textbook examples of a Stromgren sphere surrounded by an annular photodissociation region (PDR). The annular PDR is observed in both the 21 cm atomic hydrogen emission and the dust (PAH) emission near 8 micron (MSX Survey). An ultracompact radio continuum source is observed in the direction of the annular PDR, in both Sh 217 and Sh 219. JHKobservations show the presence of highly reddened stellar clusters (AV ~ 20 mag) in the directions of these radio sources. These clusters are also IRAS sources, of luminosities 22700 Lo for Sh 217 and 5900 Lo for Sh 219. Each cluster contains at least one luminous star with an IR colour excess; the one in the Sh 219 cluster shows H-alpha emission. The cluster associated with Sh 217 is almost spherical and contains luminous objects at its centre. The cluster associated with Sh 219 is elongated along the ionization front of this HII region. We argue that these are `second-generation clusters', which means that the physical conditions present in the PDRs, close to the ionization fronts, have favoured the formation of clusters containing massive objects. We discuss the physical mechanisms which may be at the origin of the observed triggered star formation., 12 pages, Latex
Published: 2002

36. Theory and observations of a jet in the _ orionis region: HH 444

Author: L. López Martin, A. C. Raga, J. A. López, and J. Meaburn
Subjects: HYDRODYNAMICS, HH 444 | ISM, JETS AND OUTFLOWS [ISM], Física, Astronomía y Matemáticas, SPECTROSCOPIC [TECHNIQUES], INDIVIDUAL OBJECTS: HH 444 [ISM], JETS AND OUTFLOWS | SHOCK WAVES | TECHNIQUES, Astrophysics::Solar and Stellar Astrophysics, INDIVIDUAL OBJECTS, SPECTROSCOPIC, SHOCK WAVES, HYDRODYNAMICS | ISM, Astrophysics::Galaxy Astrophysics
Abstract: The discovery of a system of Herbig{Haro objects ejected by young, low mass stars in the Orionis region (Reipurth et al. 1998) has given rise to models of the photoionization of a neutral jet by an external source. We present long{slit spectra of high spectral resolution of HH 444 and nu- merical simulations for this Herbig{Haro object using \yguazu , a 3D gasdynamic +radiative transfer code (Raga et al. 1999). We nd that a velocity prole in the jet beam is necessary to explain the observed accelaration in the position{velocity diagram of the HH jet. We also need also assume a non{zero opening angle at the base of the jet to explain the decreasing H intensity at increasing distances from the source and a variable ejection velocity to reproduce the well separated knots observed along the jet.
Published: 2001

37. SEARCH FOR THE 1.67 MU-M PAH EMISSION BAND - MORE UPPER LIMITS

Subjects: PLANETARY NEBULAE, HE-2-77, CONTINUUM EMISSION, INTERSTELLAR MEDIUM, INDIVIDUAL, SPECTROSCOPY, IRAS SOURCES, RED RECTANGLE, INFRARED-EMISSION, FEATURES, DUST, INDIVIDUAL OBJECTS, ORION BAR, POLYCYCLIC AROMATIC-HYDROCARBONS, CARBON, EXTINCTION, SPECTRA, NEBULAE, INTERSTELLAR DUST
Abstract: In an attempt to further resolve the origin and excitation mechanism of the unidentified infrared emission bands, we have obtained high resolution spectroscopy in the H-band for three objects with strong 3.28 and 3.4 mu m emission features. In the scenario of highly vibrational excited, isolated, polycyclic aromatic hydrocarbons a broad band resonance at about 1.67 mu m with an intensity of I-3.4/I-1.67 less than or equal to 6 has been predicted, that should be detectable for our three objects: the Orion bar at position 4, He2-77 and the Red Rectangle. However, this prediction has not been confirmed by us. Our upper limits show that the intensity of the second harmonic should be at least 48 times weaker than the intensity of the 3.4 mu m C-H stretching mode. We conclude that both the hot band theory and the explanation that the excitation of the 3.4 mu m feature is due to molecular side groups is questionable. More laboratory data such as measurements of the first overtone emission of PAH structures like cyclopropylidene (C3H2) and phenanthereneare (C10H14) are needed.

38. MAGIC reveals a complex morphology within the unidentified gamma-ray source HESS J1857+026

Author: K. Frantzen, Tihomir Surić, P. Temnikov, Fabio Zandanel, Patrick Vogler, Daniel Ferenc, V. Kadenius, R. Zanin, S. Paiano, Karl Mannheim, Alicia López-Oramas, Natalia Lewandowska, M. V. Fonseca, A. La Barbera, A. Saggion, X. Paredes-Fortuny, M. Palatiello, Adrian Biland, Nina Nowak, I. Lozano, K. Nishijima, F. Borracci, G. De Caneva, I. Snidaric, Masahiro Teshima, Christian Fruck, Stefano Covino, J. Becerra González, E. Lorenz, U. Menzel, J. Rico, D. Dominis Prester, Francesco Dazzi, Mario Meucci, S. Sun, A. González Muñoz, Diego F. Torres, M. Uellenbeck, Dario Hrupec, Stefano Ansoldi, Riccardo Paoletti, L. A. Antonelli, D. Tescaro, A. Sillanpää, M. A. Lopez, S. Rügamer, Juan Abel Barrio, Fabrizio Tavecchio, Ll. Font, D. Garrido Terrats, M. Garczarczyk, D. Nakajima, Nikola Godinovic, Benito Marcote, J. Krause, Hajime Takami, B. De Lotto, Francisco Prada, Emanuele Paolo Farina, K. Saito, S. Klepser, Nijil Mankuzhiyil, P. Munar-Adrover, Silvia Preziuso, Wlodek Bednarek, Alessandro Carosi, J. M. Paredes, Antonio Stamerra, V. Scalzotto, L. Maraschi, Elina Lindfors, K. Kodani, Abelardo Moralejo, Daniel Mazin, T. Steinbring, Ruben Lopez-Coto, Jose Miguel Miranda, P. G. Prada Moroni, K. Mallot, Thomas Bretz, S. N. Shore, Hanna Kellermann, J. Storz, A. Herrero, R. J. García López, O. Tibolla, Ana Babić, M. I. Martínez, W. Idec, G. Maneva, A. De Angelis, C. Schultz, V. Scapin, Yusuke Konno, Felix Spanier, Aaron Dominguez, J. Kushida, R. Reinthal, S. Bonnefoy, Wolfgang Rhode, E. Colombo, Dominik Elsaesser, U. Barres de Almeida, Takashi Saito, Jose Luis Contreras, M. Hayashida, Damir Lelas, Sabrina Einecke, S. R. Gozzini, R. Mirzoyan, D. Eisenacher, L. O. Takalo, Giacomo Bonnoli, Dorota Sobczyńska, J. Rodriguez Garcia, Juan Cortina, Reiko Orito, E. Carmona, Mosè Mariotti, A.-K. Overkemping, Marc Ribó, Massimo Persic, P. Bangale, Hidetoshi Kubo, Marcel Strzys, E. Prandini, Saverio Lombardi, D. Hildebrand, Aldo Treves, Ivica Puljak, Kari Nilsson, Pierre Colin, Tomislav Terzić, E. de Oña Wilhelmi, Julia Thaele, T. Schweizer, P. Antoranz, D. Fidalgo Carreto, S. Partini, C. Delgado Mendez, Daniela Dorner, M. Gaug, J. Herrera, Koji Noda, Elisa Bernardini, Martin Makariev, Oscar Blanch, M. Doert, Victor Stamatescu, Julian Sitarek, J. Hose, Daniela Hadasch, T. Toyama, Jelena Aleksić, A. Niedzwiecki, David Paneque, P. Da Vela, Robert Wagner, Konstancja Satalecka, and Michele Doro
Subjects: Acceleration of particles - gamma rays, HII regions, PSR J1856+0245, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Individual, Astrophysics, 01 natural sciences, Power law, Pulsar wind nebula, ISM: clouds, Coincidence, Clouds - HII regions - ISM, HESS J1857+026 -pulsars, Individual objects, ISM - ISM, Astronomy and Astrophysics, Space and Planetary Science, gamma rays: ISM, Pulsar, 0103 physical sciences, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, acceleration of particles, High Energy Astrophysical Phenomena (astro-ph.HE), astro-ph.HE, Physics, 010308 nuclear & particles physics, Molecular cloud, Gamma ray, Galactic plane, pulsars: individual: PSR J1856+0245, ISM: individual objects: HESS J1857+026, gamma-rays: ISM, Hii regions, ddc:520, Spectral energy distribution, Electrónica, Física nuclear, High Energy Physics::Experiment, Electricidad, Astrophysics - High Energy Astrophysical Phenomena
Abstract: HESS J1857+026 is an extended TeV gamma-ray source that was discovered by H.E.S.S. as part of its Galactic plane survey. Given its broadband spectral energy distribution and its spatial coincidence with the young energetic pulsar PSR J1856+0245, the source has been put forward as a pulsar wind nebula (PWN) candidate. MAGIC has performed follow-up observations aimed at mapping the source down to energies approaching 100 GeV in order to better understand its complex morphology. HESS J1857+026 was observed by MAGIC in 2010, yielding 29 hours of good quality stereoscopic data that allowed us to map the source region in two separate ranges of energy. We detected very-high-energy gamma-ray emission from HESS J1857+026 with a significance of $12 \sigma$ above $150$ GeV. The differential energy spectrum between $100$ GeV and $13$ TeV is well described by a power law function $dN/dE = N_0(E/1\textrm{TeV})^{-\Gamma}$ with $N_0 = (5.37 \pm0.44_{stat} \pm1.5_{sys}) \times 10^{-12} (\textrm{TeV}^{-1} \textrm{cm}^{-2}$ $\textrm{ s}^{-1})$ and $\Gamma = 2.16\pm0.07_{stat} \pm0.15_{sys}$, which bridges the gap between the GeV emission measured by Fermi-LAT and the multi-TeV emission measured by H.E.S.S.. In addition, we present a detailed analysis of the energy-dependent morphology of this region. We couple these results with archival multi-wavelength data and outline evidence in favor of a two-source scenario, whereby one source is associated with a PWN, while the other could be linked with a molecular cloud complex containing an HII region and a possible gas cavity., Comment: 9 pages, 6 figures. Accepted for publication in A&A

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