107 results on '"Bland-Hawthorn, J"'
Search Results
2. SAMI Galaxy Survey: physical drivers of stellar-gas kinematic misalignments in the nearby Universe.
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Ristea, A, Cortese, L, Fraser-McKelvie, A, Brough, S, Bryant, J J, Catinella, B, Croom, S M, Groves, B, Richards, S N, van de Sande, J, Bland-Hawthorn, J, Owers, M S, and Lawrence, J S
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GALACTIC evolution ,STELLAR rotation ,UNIVERSE ,DRAG force ,STAR formation - Abstract
Misalignments between the rotation axis of stars and gas are an indication of external processes shaping galaxies throughout their evolution. Using observations of 3068 galaxies from the SAMI Galaxy Survey, we compute global kinematic position angles for 1445 objects with reliable kinematics and identify 169 (12 per cent) galaxies which show stellar-gas misalignments. Kinematically decoupled features are more prevalent in early-type/passive galaxies compared to late-type/star-forming systems. Star formation is the main source of gas ionization in only 22 per cent of misaligned galaxies; 17 per cent are Seyfert objects, while 61 per cent show Low-Ionization Nuclear Emission-line Region features. We identify the most probable physical cause of the kinematic decoupling and find that, while accretion-driven cases are dominant, for up to 8 per cent of our sample, the misalignment may be tracing outflowing gas. When considering only misalignments driven by accretion, the acquired gas is feeding active star formation in only ∼1/4 of cases. As a population, misaligned galaxies have higher Sérsic indices and lower stellar spin and specific star formation rates than appropriately matched samples of aligned systems. These results suggest that both morphology and star formation/gas content are significantly correlated with the prevalence and timescales of misalignments. Specifically, torques on misaligned gas discs are smaller for more centrally concentrated galaxies, while the newly accreted gas feels lower viscous drag forces in more gas-poor objects. Marginal evidence of star formation not being correlated with misalignment likelihood for late-type galaxies suggests that such morphologies in the nearby Universe might be the result of preferentially aligned accretion at higher redshifts. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
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3. physical connection between central stellar surface density and stellar spin in SAMI and MaNGA nearby galaxies.
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Cortese, L, Fraser-McKelvie, A, Woo, J, Catinella, B, Harborne, K E, van de Sande, J, Bland-Hawthorn, J, Brough, S, Bryant, J J, Croom, S, and Sweet, S
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GALAXIES ,STAR formation ,ASTRONOMICAL surveys ,GALACTIC evolution ,DENSITY ,STELLAR mass ,GALACTIC bulges - Abstract
The stellar surface density within the inner 1 kpc (Σ
1 ) has become a popular tool for understanding the growth of galaxies and its connection with the quenching of star formation. The emerging picture suggests that building a central dense core is a necessary condition for quenching. However, it is not clear whether changes in Σ1 trace changes in stellar kinematics and the growth of dispersion-dominated bulges. In this paper, we combine imaging from the Sloan Digital Sky Survey with stellar kinematics from the Sydney-AAO Multi-object Integral-field unit and Mapping Nearby Galaxies at Apache Point Observatory surveys to quantify the correlation between Σ1 and the proxy for stellar spin parameter within one effective radius (λre ) for 1599 nearby galaxies. We show that, on the star-forming main sequence and at fixed stellar mass, changes in Σ1 are mirrored by changes in λre . While forming stars, main-sequence galaxies remain rotationally-dominated systems, with their Σ1 increasing but their stellar spin staying either constant or slightly increasing. The picture changes below the main sequence, where Σ1 and λre are no longer correlated. Passive systems show a narrower range of Σ1 , but a wider range of λre compared to star-forming galaxies. Our results indicate that, from a structural point of view, passive galaxies are a more heterogeneous population than star-forming systems, and may have followed a variety of evolutionary paths. This also suggests that, if dispersion-dominated bulges still grow significantly at z ∼ 0, this generally takes place during, or after, the quenching phase. [ABSTRACT FROM AUTHOR]- Published
- 2022
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4. SAMI Galaxy Survey: the drivers of gas and stellar metallicity differences in galaxies.
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Fraser-McKelvie, A, Cortese, L, Groves, B, Brough, S, Bryant, J, Catinella, B, Croom, S, D'Eugenio, F, López-Sánchez, Á R, van de Sande, J, Sweet, S, Vaughan, S, Bland-Hawthorn, J, Lawrence, J, Lorente, N, and Owers, M
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GALAXIES ,GALACTIC evolution ,INTERSTELLAR medium ,GRAVITATIONAL potential ,GALAXY formation - Abstract
The combination of gas-phase oxygen abundances and stellar metallicities can provide us with unique insights into the metal enrichment histories of galaxies. In this work, we compare the stellar and gas-phase metallicities measured within a 1 R
e aperture for a representative sample of 472 star-forming galaxies extracted from the SAMI Galaxy Survey. We confirm that the stellar and interstellar medium (ISM) metallicities are strongly correlated, with scatter ∼3 times smaller than that found in previous works, and that integrated stellar populations are generally more metal-poor than the ISM, especially in low-mass galaxies. The ratio between the two metallicities strongly correlates with several integrated galaxy properties including stellar mass, specific star formation rate, and a gravitational potential proxy. However, we show that these trends are primarily a consequence of: (a) the different star formation and metal enrichment histories of the galaxies, and (b) the fact that while stellar metallicities trace primarily iron enrichment, gas-phase metallicity indicators are calibrated to the enrichment of oxygen in the ISM. Indeed, once both metallicities are converted to the same 'element base' all of our trends become significantly weaker. Interestingly, the ratio of gas to stellar metallicity is always below the value expected for a simple closed-box model, which requires that outflows and inflows play an important role in the enrichment history across our entire stellar mass range. This work highlights the complex interplay between stellar and gas-phase metallicities and shows how care must be taken in comparing them to constrain models of galaxy formation and evolution. [ABSTRACT FROM AUTHOR]- Published
- 2022
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5. The SAMI Galaxy Survey: the role of disc fading and progenitor bias in kinematic transitions.
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Croom, S M, Taranu, D S, van de Sande, J, Lagos, C D P, Harborne, K E, Bland-Hawthorn, J, Brough, S, Bryant, J J, Cortese, L, Foster, C, Goodwin, M, Groves, B, Khalid, A, Lawrence, J, Medling, A M, Richards, S N, Owers, M S, Scott, N, and Vaughan, S P
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DISK galaxies ,GALAXIES ,STELLAR populations ,STAR formation ,GALACTIC evolution ,SPIRAL galaxies - Abstract
We use comparisons between the Sydney-AAO Multi-object Integral Field Spectrograph (SAMI) Galaxy Survey and equilibrium galaxy models to infer the importance of disc fading in the transition of spirals into lenticular (S0) galaxies. The local S0 population has both higher photometric concentration and lower stellar spin than spiral galaxies of comparable mass and we test whether this separation can be accounted for by passive aging alone. We construct a suite of dynamically self-consistent galaxy models, with a bulge, disc, and halo using the galactics code. The dispersion-dominated bulge is given a uniformly old stellar population, while the disc is given a current star formation rate putting it on the main sequence, followed by sudden instantaneous quenching. We then generate mock observables (r -band images, stellar velocity, and dispersion maps) as a function of time since quenching for a range of bulge/total (B / T) mass ratios. The disc fading leads to a decline in measured spin as the bulge contribution becomes more dominant, and also leads to increased concentration. However, the quantitative changes observed after 5 Gyr of disc fading cannot account for all of the observed difference. We see similar results if we instead subdivide our SAMI Galaxy Survey sample by star formation (relative to the main sequence). We use EAGLE simulations to also take into account progenitor bias, using size evolution to infer quenching time. The EAGLE simulations suggest that the progenitors of current passive galaxies typically have slightly higher spin than present day star-forming disc galaxies of the same mass. As a result, progenitor bias moves the data further from the disc fading model scenario, implying that intrinsic dynamical evolution must be important in the transition from star-forming discs to passive discs. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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6. A SAMI and MaNGA view on the stellar kinematics of galaxies on the star-forming main sequence.
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Fraser-McKelvie, A, Cortese, L, van de Sande, J, Bryant, J J, Catinella, B, Colless, M, Croom, S M, Groves, B, Medling, A M, Scott, N, Sweet, S M, Bland-Hawthorn, J, Goodwin, M, Lawrence, J, Lorente, N, Owers, M S, and Richards, S N
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DISK galaxies ,GALAXIES ,STELLAR structure ,STELLAR mass ,GALAXY formation ,GALACTIC bulges ,STELLAR activity - Abstract
Galaxy internal structure growth has long been accused of inhibiting star formation in disc galaxies. We investigate the potential physical connection between the growth of dispersion-supported stellar structures (e.g. classical bulges) and the position of galaxies on the star-forming main sequence at z ∼ 0. Combining the might of the SAMI and MaNGA galaxy surveys, we measure the λ
Re spin parameter for 3289 galaxies over |$9.5 \lt \log M_{\star } [\rm {M}_{\odot }] \lt 12$|. At all stellar masses, galaxies at the locus of the main sequence possess λRe values indicative of intrinsically flattened discs. However, above |$\log M_{\star }[\rm {M}_{\odot }]\sim 10.5$| where the main sequence starts bending, we find tantalizing evidence for an increase in the number of galaxies with dispersion-supported structures, perhaps suggesting a connection between bulges and the bending of the main sequence. Moving above the main sequence, we see no evidence of any change in the typical spin parameter in galaxies once gravitationally interacting systems are excluded from the sample. Similarly, up to 1 dex below the main sequence, λRe remains roughly constant and only at very high stellar masses (|$\log M_{\star }[\rm {M}_{\odot }]\gt 11$|), do we see a rapid decrease in λRe once galaxies decline in star formation activity. If this trend is confirmed, it would be indicative of different quenching mechanisms acting on high- and low-mass galaxies. The results suggest that whilst a population of galaxies possessing some dispersion-supported structure is already present on the star-forming main sequence, further growth would be required after the galaxy has quenched to match the kinematic properties observed in passive galaxies at z ∼ 0. [ABSTRACT FROM AUTHOR]- Published
- 2021
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7. Stellar kinematics across the Hubble sequence in the CALIFA survey: general properties and aperture corrections
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Falc��n-Barroso, J., Lyubenova, M., van de Ven, G., M��ndez-Abreu, J., Aguerri, J. A. L., Garc��a-Lorenzo, B., Bekeraite, S., S��nchez, S. F., Husemann, B., Garc��a-Benito, R., Mast, D., Walcher, C. J., Zibetti, S., Barrera-Ballesteros, J. K., Galbany, L., S��nchez-Bl��zquez, P., Singh, R., Bosch, R. C. E. van den, Wild, V., Zhu, L., Bland-Hawthorn, J., Fernandes, R. Cid, de Lorenzo-C��ceres, A., Gallazzi, A., Delgado, R. M. Gonz��lez, Marino, R. A., M��rquez, I., P��rez, E., P��rez, I., Roth, M. M., Rosales-Ortega, F. F., Ru��z-Lara, T., Wisotzki, L., Ziegler, B., collaboration, the CALIFA, Astronomy, Ministerio de Economía y Competitividad (España), European Commission, European Research Council, and University of St Andrews. School of Physics and Astronomy
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Astrofísica ,POTSDAM MULTIAPERTURE SPECTROPHOTOMETER ,Ciencias Físicas ,structure [Galaxies] ,Astrophysics ,Kinematics ,01 natural sciences ,Hubble sequence ,purl.org/becyt/ford/1 [https] ,elliptical and lenticular [Galaxies] ,Range (statistics) ,QB Astronomy ,EARLY-TYPE GALAXIES ,EMISSION-LINE KINEMATICS ,galaxies: elliptical and lenticular ,010303 astronomy & astrophysics ,QC ,galaxies: kinematics and dynamics ,QB ,Physics ,Basis (linear algebra) ,kinematics and dynamics [Galaxies] ,Velocity dispersion ,Galaxies: elliptical and lenticular, cD ,stucture [Galaxies] ,FIELD AREA SURVEY ,symbols ,galaxies: structure ,galaxies: evolution ,CIENCIAS NATURALES Y EXACTAS ,Stellar kinematics ,galaxies: spiral ,Aperture ,FOS: Physical sciences ,Astrophysics::Cosmology and Extragalactic Astrophysics ,elliptical and lenticular, cD [Galaxies] ,PUBLIC DATA RELEASE ,cD ,symbols.namesake ,ELLIPTIC GALAXIES ,0103 physical sciences ,galaxies: formation ,Astrophysics::Galaxy Astrophysics ,LENTICULAR GALAXIES ,spiral [Galaxies] ,010308 nuclear & particles physics ,DAS ,Astronomy and Astrophysics ,purl.org/becyt/ford/1.3 [https] ,evolution [Galaxies] ,Astrophysics - Astrophysics of Galaxies ,formation [Galaxies] ,SAURON PROJECT ,Galaxy ,Astronomía ,QC Physics ,Space and Planetary Science ,Astrophysics of Galaxies (astro-ph.GA) ,DIGITAL SKY SURVEY ,SIGHT VELOCITY DISTRIBUTIONS - Abstract
J. Falcón-Barroso et. al., We present the stellar kinematic maps of a large sample of galaxies from the integral-field spectroscopic survey CALIFA. The sample comprises 300 galaxies displaying a wide range of morphologies across the Hubble sequence, from ellipticals to late-type spirals. This dataset allows us to homogeneously extract stellar kinematics up to several effective radii. In this paper, we describe the level of completeness of this subset of galaxies withrespect to the full CALIFA sample, as well as the virtues and limitations of the kinematic extraction compared to other well-known integral-field surveys. In addition, we provide averaged integrated velocity dispersion radial profiles for different galaxy types, which are particularly useful to apply aperture corrections for single aperture measurements or poorly resolved stellar kinematics of high-redshift sources. The work presented in this paper sets the basis for the study of more general properties of galaxies that will be explored in subsequent papers of the survey.© ESO, 2016., J.F.-B. from grant AYA2013-48226-C3-1-P from the Spanish Ministry of Economy and Competitiveness (MINECO). J.F.-B. and G.v.d.V. from the FP7 Marie Curie Actions of the European Commission, via the Initial Training Network DAGAL under REA grant agreement number 289313. J.M.-A. and V.W. acknowledge support from the European Research Council Starting Grant (SEDMorph P.I. V. Wild). P.S.-B. acknowledge financial support from the BASAL CATA Center for Astrophysics and Associated Technologies through grant PFB-06. R.M.G.D. from grant AYA2014-57490-P. R.G.-B, R.M.G.D. and E.P. acknowledge support from the project JA-FQM-2828. C.J.W. acknowledges support through the Marie Curie Career Integration Grant 303912. L.G. from the Ministry of Economy, Development, and Tourism's Millennium Science Initiative through grant IC120009 awarded to The Millennium Institute of Astrophysics (MAS), and CONICYT through FONDECYT grant 3140566. I.M. from grant AYA2013-42227-P.
- Published
- 2017
8. The SAMI Galaxy Survey: first detection of a transition in spin orientation with respect to cosmic filaments in the stellar kinematics of galaxies.
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Welker, C, Bland-Hawthorn, J, Van de Sande, J, Lagos, C, Elahi, P, Obreschkow, D, Bryant, J, Pichon, C, Cortese, L, Richards, S N, Croom, S M, Goodwin, M, Lawrence, J S, Sweet, S, Lopez-Sanchez, A, Medling, A, Owers, M S, Dubois, Y, and Devriendt, J
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GALAXY formation , *SPIN crossover , *FIBERS , *GALAXIES , *STELLAR mergers , *KINEMATICS - Abstract
We present the first detection of mass-dependent galactic spin alignments with local cosmic filaments with >2σ confidence using IFS kinematics. The 3D network of cosmic filaments is reconstructed on Mpc scales across GAlaxy and Mass Assembly fields using the cosmic web extractor DisPerSe. We assign field galaxies from the SAMI survey to their nearest filament segment in 3D and estimate the degree of alignment between SAMI galaxies' kinematic spin axis and their nearest filament in projection. Low-mass galaxies align their spin with their nearest filament while higher mass counterparts are more likely to display an orthogonal orientation. The stellar transition mass from the first trend to the second is bracketed between |$10^{10.4}$| and |$10^{10.9}\, \mathrm{ M}_{\odot }$| , with hints of an increase with filament scale. Consistent signals are found in the Horizon-AGN cosmological hydrodynamic simulation. This supports a scenario of early angular momentum build-up in vorticity rich quadrants around filaments at low stellar mass followed by progressive flip of spins orthogonal to the cosmic filaments through mergers at high stellar mass. Conversely, we show that dark matter only simulations post-processed with a semi-analytical model treatment of galaxy formation struggles to reproduce this alignment signal. This suggests that gas physics is key in enhancing the galaxy-filament alignment. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
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9. Star formation along the Hubble sequence: Radial structure of the star formation of CALIFA galaxies
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González Delgado, RM, Cid Fernandes, R, Pérez, E, García-Benito, R, López Fernández, R, Lacerda, EAD, Cortijo-Ferrero, C, De Amorim, AL, Vale Asari, N, Sánchez, SF, Walcher, CJ, Wisotzki, L, Mast, D, Alves, J, Ascasibar, Y, Bland-Hawthorn, J, Galbany, L, Kennicutt, RC, Márquez, I, Masegosa, J, Mollá, M, Sánchez-Blázquez, P, Vílchez, JM, Kennicutt, Robert [0000-0001-5448-1821], and Apollo - University of Cambridge Repository
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galaxies: star formation ,galaxies: stellar content ,galaxies: evolution ,techniques: spectroscopic - Abstract
© ESO, 2016. The spatially resolved stellar population content of today's galaxies holds important information for understanding the different processes that contribute to the star formation and mass assembly histories of galaxies. The aim of this paper is to characterize the radial structure of the star formation rate (SFR) in galaxies in the nearby Universe as represented by a uniquely rich and diverse data set drawn from the CALIFA survey. The sample under study contains 416 galaxies observed with integral field spectroscopy, covering a wide range of Hubble types and stellar masses ranging from M∗ ∼ 109 to 7 × 1011 M⊙. Spectral synthesis techniques are applied to the datacubes to derive 2D maps and radial profiles of the intensity of the star formation rate in the recent past (ΣSFR), as well as related properties, such as the local specific star formation rate (sSFR), defined as the ratio between ΣSFR and the stellar mass surface density (μ∗). To emphasize the behavior of these properties for galaxies that are on and off the main sequence of star formation (MSSF), we stack the individual radial profiles in seven bins of galaxy morphology (E, S0, Sa, Sb, Sbc, Sc, and Sd), and several stellar masses. Our main results are: (a) the intensity of the star formation rate shows declining profiles that exhibit very small differences between spirals with values at R = 1 half light radius (HLR) within a factor two of ΣSFR ∼ 20 M⊙Gyr-1pc-2. The dispersion in the ΣSFR(R) profiles is significantly smaller in late type spirals (Sbc, Sc, Sd). This confirms that the MSSF is a sequence of galaxies with nearly constant ΣSFR. (b) sSFR values scale with Hubble type and increase radially outward with a steeper slope in the inner 1 HLR. This behavior suggests that galaxies are quenched inside-out and that this process is faster in the central, bulge-dominated part than in the disks. (c) As a whole and at all radii, E and S0 are off the MSSF with SFR much smaller than spirals of the same mass. (d) Applying the volume corrections for the CALIFA sample, we obtain a density of star formation in the local Universe of ρSFR = (0.0105 ± 0.0008) M⊙yr-1Mpc-3, in agreement with independent estimates. Most of the star formation is occurring in the disks of spirals. (e) The volume-averaged birthrate parameter, which measures the current SFR with respect to its lifetime average, b′ = 0.39 ± 0.03, suggests that the present day Universe is forming stars a about one-third of its past average rate. E, S0, and the bulge of early type spirals (Sa, Sb) contribute little to the recent SFRof the Universe, which is dominated by the disks of Sbc, Sc, and Sd spirals. (f) There is a tight relation between ΣSFR and μ∗, defining a local MSSF relation with a logarithmic slope of 0.8, similar to the global MSSF relation between SFR and M∗. This suggests that local processes are important in determining the star formation in disks, probably through a density dependence of the SFR law. The scatter in the local MSSF is driven by morphology-related offsets, with ΣSFR/μ∗ (the local sSFR) increasing from early to late type galaxies, indicating that the shut down of the star formation is more related to global processes, such as the formation of a spheroidal component.
- Published
- 2016
10. Outer-disk reddening and gas-phase metallicities: The CALIFA connection
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Sánchez-Blázquez, Patricia, Marino, R. A., Gil De Paz, A., Sánchez, S. F., Cardiel, N., Castillo- Morales, A., Pascual, S., Vílchez, J., Kehrig, C., Mollá, M., Méndez-Abreu, Jairo, Catalán-Torrecilla, C., Florido, E., Perez, I., Ruiz-Lara, T., Ellis, S., López-Sánchez, A. R., González Delgado, R.M, De Lorenzo-Cáceres, A., García-Benito, R., Galbany, L., Cortijo, C., Kalinova, V., Mast, D., Iglesias-Páramo, J., Papaderos, P., Walcher, C.J., Bland-Hawthorn, J., Zibetti, S., CALIFA Team, UAM. Departamento de Física Teórica, Campus de Excelencia Internacional Moncloa, Ministerio de Economía y Competitividad (España), European Commission, Ministerio de Educación, Cultura y Deporte (España), Instituto Milenio de Astrofísica (Chile), Comisión Nacional de Investigación Científica y Tecnológica (Chile), Fondo Nacional de Desarrollo Científico y Tecnológico (Chile), Consejo Nacional de Ciencia y Tecnología (México), European Research Council, and Fundação para a Ciência e a Tecnologia (Portugal)
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Astrofísica ,Stellar mass ,Galaxies: abundances ,Hii regions ,Ciencias Físicas ,Metallicity ,Population ,FOS: Physical sciences ,ISM [GALAXIES] ,Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Type (model theory) ,01 natural sciences ,Flattening ,ISM: abundances ,purl.org/becyt/ford/1 [https] ,HII REGIONS ,0103 physical sciences ,ABUNDANCES [ISM] ,Surface brightness ,ABUNDANCES [GALAXIES] ,education ,010303 astronomy & astrophysics ,Astrophysics::Galaxy Astrophysics ,EVOLUTION [GALAXIES] ,Physics ,education.field_of_study ,010308 nuclear & particles physics ,Star formation ,Galaxies: evolution ,Física ,Astronomy and Astrophysics ,Galaxies: photometry ,PHOTOMETRY [GALAXIES] ,purl.org/becyt/ford/1.3 [https] ,Astrophysics - Astrophysics of Galaxies ,Galaxy ,Astronomía ,Galaxies: ISM ,Space and Planetary Science ,Astrophysics of Galaxies (astro-ph.GA) ,Astrophysics::Earth and Planetary Astrophysics ,CIENCIAS NATURALES Y EXACTAS - Abstract
Based on observations collected at the German-Spanish Astronomical Center, Calar Alto, jointly operated by the Max-Planck-Institut für Astronomie Heidelberg and the Instituto de Astrofísica de Andalucía (CSIC )., CALIFA Team: et al., We study, for the first time in a statistically significant and well-defined sample, the relation between the outer-disk ionized-gas metallicity gradients and the presence of breaks in the surface brightness profiles of disk galaxies. Sloan Digital Sky Survey (SDSS) g′- and r′-band surface brightness, (g′ - r′) color, and ionized-gas oxygen abundance profiles for 324 galaxies within the Calar Alto Legacy Integral Field Area (CALIFA) survey are used for this purpose. We perform a detailed light-profile classification, finding that 84% of our disks show down- or up-bending profiles (Type II and Type III, respectively), while the remaining 16% are well fitted by one single exponential (Type I). The analysis of the color gradients at both sides of this break shows a U-shaped profile for most Type II galaxies with an average minimum (g′ - r′) color of ∼ 0.5mag and an ionized-gas metallicity flattening associated with it only in the case of low-mass galaxies. Comparatively, more massive systems show a rather uniform negative metallicity gradient. The correlation between metallicity flattening and stellar mass for these systems results in p-values as low as 0.01. Independent of the mechanism having shaped the outer light profiles of these galaxies, stellar migration or a previous episode of star formation in a shrinking star-forming disk, it is clear that the imprint in their ionized-gas metallicity was different for low- and high-mass Type II galaxies. In the case of Type III disks, a positive correlation between the change in color and abundance gradient is found (the null hypothesis is ruled out with a p-value of 0.02), with the outer disks of Type III galaxies with masses ≤10 M′ showing a weak color reddening or even a bluing. This is interpreted as primarily due to a mass downsizing effect on the population of Type III galaxies that recently experienced an enhanced inside-out growth., R. A. Marino is funded by the Spanish program of International Campus of Excellence Moncloa (CEI).We acknowledge support from the Plan Nacional de Investigación y Desarrollo funding programs, AyA2010-15081, AyA2012-30717 and AyA2013-46724P, of Spanish Ministerio de Economía y Competitividad (MINECO). A.G.d.P. acknowledges the support from the FP7 Marie Curie Actions of the European Commission, via the Initial Training Network DAGAL under REA grant agreement PITNGA-2011-289313. C.C.-T. thanks the support of the Spanish Ministerio de Educación, Cultura y Deporte by means of the FPU fellowship program. C.J.W. acknowledges support through the Marie Curie Career Integration Grant 303912. Support for L.G. is provided by the Ministry of Economy, Development, and Tourism’s Millennium Science Initiative through grant IC 120009, awarded to The Millennium Institute of Astrophysics, MAS. L.G. acknowledges support by CONICYT through FONDECYT grant 3140566. S.F.S. thanks the CONACYT-125180 and DGAPA-IA100815 projects for providing him support in this study. J.M.A. acknowledges support from the European Research Council Starting Grant (SEDmorph; P.I. V. Wild). P.P. is supported by FCT through the Investigador FCT Contract No. IF/01220/2013 and POPH/FSE (EC) by FEDER funding through the program COMPETE. He also acknowledges support by FCT under project FCOMP-01-0124-FEDER-029170 (Reference FCT PTDC/FISAST/3214/2012), funded by FCT-MEC (PIDDAC) and FEDER (COMPETE).
- Published
- 2016
11. Tracing kinematic (mis)alignments in CALIFA merging galaxies. Stellar and ionized gas kinematic orientations at every merger stage
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Barrera-Ballesteros, J. K., Garc��a-Lorenzo, B., Falc��n-Barroso, J., van de Ven, G., Lyubenova, M., Wild, V., M��ndez-Abreu, J., S��nchez, S. F., Marquez, I., Masegosa, J., Monreal-Ibero, A., Ziegler, B., del Olmo, A., Verdes-Montenegro, L., Garc��a-Benito, R., Husemann, B., Mast, D., Kehrig, C., Iglesias-Paramo, J., Marino, R. A., Aguerri, J. A. L., Walcher, C. J., V��lchez, J. M., Bomans, D. J., Cortijo-Ferrero, C., Delgado, R. M. Gonz��lez, Bland-Hawthorn, J., McIntosh, D. H., Bekeraite, Simona, Collaboration, the CALIFA, European Research Council, University of St Andrews. School of Physics and Astronomy, Astronomy, Kapteyn Astronomical Institute, Ministerio de Ciencia e Innovación (España), Ministerio de Economía, Industria y Competitividad (España), and Junta de Andalucía
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Astrofísica ,media_common.quotation_subject ,Ciencias Físicas ,FOS: Physical sciences ,Astrophysics ,Kinematics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,interactions [Galaxies] ,Galaxy merger ,Measure (mathematics) ,purl.org/becyt/ford/1 [https] ,statistics [Galaxies] ,Position (vector) ,galaxies: interactions ,kinematics [Galaxies] ,Astrophysics::Galaxy Astrophysics ,QC ,galaxies: kinematics and dynamics ,galaxies: statistics ,media_common ,Physics ,Astronomy and Astrophysics ,DAS ,purl.org/becyt/ford/1.3 [https] ,Plasma ,evolution [Galaxies] ,Astrophysics - Astrophysics of Galaxies ,Universe ,Galaxy ,Redshift ,Astronomía ,QC Physics ,Space and Planetary Science ,Astrophysics of Galaxies (astro-ph.GA) ,galaxies: evolution ,CIENCIAS NATURALES Y EXACTAS ,KINEMATICS AND DYNAMICS [GALAXIES] - Abstract
© 2015 ESO. We present spatially resolved stellar and/or ionized gas kinematic properties for a sample of 103 interacting galaxies, tracing all merger stages: close companions, pairs with morphological signatures of interaction, and coalesced merger remnants. In order to distinguish kinematic properties caused by a merger event from those driven by internal processes, we compare our galaxies with a control sample of 80 non-interacting galaxies. We measure for both the stellar and the ionized gas components the major (projected) kinematic position angles (PAkin, approaching and receding) directly from the velocity distributions with no assumptions on the internal motions. This method also allow us to derive the deviations of the kinematic PAs from a straight line (δPAkin). We find that around half of the interacting objects show morpho-kinematic PA misalignments that cannot be found in the control sample. In particular, we observe those misalignments in galaxies with morphological signatures of interaction. On the other hand, thelevel of alignment between the approaching and receding sides for both samples is similar, with most of the galaxies displaying small misalignments. Radial deviations of the kinematic PA orientation from a straight line in the stellar component measured by δPAkin are large for both samples. However, for a large fraction of interacting galaxies the ionized gas δPAkin is larger than the typical values derived from isolated galaxies (48%), indicating that this parameter is a good indicator to trace the impact of interaction and mergers in the internal motions of galaxies. By comparing the stellar and ionized gas kinematic PA, we find that 42% (28/66) of the interacting galaxies have misalignments larger than 16°, compared to 10% from the control sample. Our results show the impact of interactions in the motion of stellar and ionized gas as well as the wide the variety of their spatially resolved kinematic distributions. This study also provides a local Universe benchmark for kinematic studies in merging galaxies at high redshift., J.B.-B. and B.G.-L acknowledge support from the Plan Nacional de I+D+i (PNAYA) funding programs (AYA2012-39408-C02-02-1 and AYA2013-41656-P) of Spanish Ministry of Economy and Competitiveness (MINECO). J.F.B. acknowledges support from the Plan Nacional de I+D+i (PNAYA) funding programs from MINECO (AYA2013-48226-03-1-P, RAVET) A.M.-I. acknowledges support from Agence Nationale de la Recherche through the STILISM project (ANR-12-BS05-0016-02) and from BMBF through the Erasmus-F project (grant number 05 A12BA1). I.M. acknowledges financial support by MINECO grant AYA 2010-15169, Junta de Andalucia TIC114 and Proyecto de Excelencia de la Junta de Andalucia P08-TIC-03531. J.M.A. and V.W. acknowledge support from the European Research Council Starting Grant (SEDmorph; P.I. V. Wild). J.I.P. acknowledges financial support from the Spanish MINECO under grant AYA2013-47742-C04-1 and from Junta de Andalucia Excellence Project PEX2011-FQM7058. R.A.M is funded by the Spanish program of International Campus of Excellence Moncloa (CEI). L.V.M. acknowledges support from the grant AYA2011-30491-C02-01 co-financed by MICINN and FEDER funds, and the Junta de Andalucia (Spain) grants P08-FQM-4205 and TIC-114.
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- 2015
12. Ionized gas kinematics of galaxies in the CALIFA survey: I. Velocity fields, kinematic parameters of the dominant component, and presence of kinematically distinct gaseous systems
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García-Lorenzo, B., Márquez, I., Barrera-Ballesteros, J. K., Masegosa, J., Husemann, B., Falcón-Barroso, J., Lyubenova, M., Sánchez, S. F., Walcher, J., Mast, D., García-Benito, R., Méndez-Abreu, Jairo, Van De Ven, Glenn, Spekkens, K., Holmes, L., Monreal-Ibero, Ana, Del Olmo, A., Ziegler, B., Bland-Hawthorn, J., Sánchez-Blázquez, Patricia, Iglesias-Páramo, J., Aguerri, J. Alfonso L, Papaderos, P., Gomes, J. M., Marino, R. A., González Delgado, R. M., Cortijo-Ferrero, C., López-Sánchez, A. R., Bekeraite, S., Wisotzki, L., Bomans, D., CALIFA team, UAM. Departamento de Física Teórica, European Research Council, and University of St Andrews. School of Physics and Astronomy
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Field (physics) ,FOS: Physical sciences ,Techniques: spectroscopic ,Kinematics ,Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,elliptical and lenticular, cD [Galaxies] ,01 natural sciences ,star formation [Galaxies] ,Displacement (vector) ,spectroscopic [Techniques] ,cD ,elliptical and lenticular [Galaxies] ,0103 physical sciences ,QB Astronomy ,Emission spectrum ,010303 astronomy & astrophysics ,QC ,Astrophysics::Galaxy Astrophysics ,QB ,Physics ,spiral [Galaxies] ,Galaxies: elliptical and lenticular ,Galaxies: star formation ,010308 nuclear & particles physics ,Component (thermodynamics) ,kinematics and dynamics [Galaxies] ,Galaxies: kinematics and dynamics ,Galaxies: evolution ,Física ,Astronomy and Astrophysics ,Plasma ,3rd-DAS ,evolution [Galaxies] ,Astrophysics - Astrophysics of Galaxies ,Galaxy ,Radial velocity ,QC Physics ,Space and Planetary Science ,Astrophysics of Galaxies (astro-ph.GA) ,Galaxies: spiral - Abstract
Astronomy and Astrophysics 573 (2015): A59 reproduced with permission from Astronomy & Astrophysics, © ESO, Context. Ionized gas kinematics provide important clues to the dynamical structure of galaxies and hold constraints to the processes driving their evolution. Aims. The motivation of this work is to provide an overall characterization of the kinematic behavior of the ionized gas of the galaxies included in the Calar Alto Legacy Integral field Area (CALIFA), offering kinematic clues to potential users of the CALIFA survey for including kinematical criteria in their selection of targets for specific studies. From the first 200 galaxies observed by CALIFA survey in its two configurations, we present the two-dimensional kinematic view of the 177 galaxies satisfaying a gas content/detection threshold. Methods. After removing the stellar contribution, we used the cross-correlation technique to obtain the radial velocity of the dominant gaseous component for each spectrum in the CALIFA data cubes for different emission lines (namely, [O II] λλ3726,3729, [O III] λλ4959,5007, Hα+[N II] λλ6548,6584, and [SII] λλ6716,6730). The main kinematic parameters measured on the plane of the sky were directly derived from the radial velocities with no assumptions on the internal prevailing motions. Evidence of the presence of several gaseous components with different kinematics were detected by using [O III] λλ4959,5007 emission line profiles. Results. At the velocity resolution of CALIFA, most objects in the sample show regular velocity fields, although the ionized-gas kinematics are rarely consistent with simple coplanar circular motions. Thirty-five percent of the objects present evidence of a displacement between the photometric and kinematic centers larger than the original spaxel radii. Only 17% of the objects in the sample exhibit kinematic lopsidedness when comparing receding and approaching sides of the velocity fields, but most of them are interacting galaxies exhibiting nuclear activity (AGN or LINER). Early-type (E+S0) galaxies in the sample present clear photometric-kinematic misaligments. There is evidence of asymmetries in the emission line profiles in 117 out of the 177 analyzed galaxies, suggesting the presence of kinematically distinct gaseous components located at different distances from the optical nucleus. The kinematic decoupling between the dominant and secondary component/s suggested by the observed asymmetries in the profiles can be characterized by a limited set of parameters. Conclusions. This work constitutes the first determination of the ionized gas kinematics of the galaxies observed in the CALIFA survey. The derived velocity fields, the reported kinematic distortions/peculiarities and the identification of the presence of several gaseous components in different regions of the objects might be used as additional criteria for selecting galaxies for specific studies, We thank the Viabilidad, Diseño, Acceso y Mejora funding program (ICTS-2009-10) for supporting the initial developement of this project. B.G.-L. and J.B.-B. thank the support from the Plan Nacional de I+D+i (PNAYA) funding programs (AYA2012- 39408-C02-02) of the Spanish Ministerio de Economía y Competitividad (MINECO). I.M., J.M. and A.d.O. acknowledge financial support from the Spanish grant AYA2010-15169 and Junta de Andalucia TIC114 and Excellence Project P08-TIC-03531. S.F.S. and D.M. also thank the support given to this project from the PNAYA of the MINECO under grant AYA2012-31935. S.F.S. thanks the Ramón y Cajal project (RyC-2011-07590) of the Spanish MINECO, for the support giving to this project. J.M.A. acknowledges support from the European Research Council Starting Grant (SEDmorph; P.I. V. Wild). We acknowledge financial support for the ESTALLIDOS collaboration by the Spanish MINECO under grant AYA2010- 21887-C04-03. J.F.-B. acknowledges financial support from the Ramón y Cajal Program and grant AYA2010-21322-C03-02 from the MINECO, as well as to the DAGAL network from the People Programme (Marie Curie Actions) of the European Unions Seventh Framework Programme FP7/2007-2013/ under REA grant agreement number PITN-GA-2011-289313. K.S. acknowledges support from the National Sciences and Engineering Research Council of Canada. A.M.-I. acknowledges support from Agence Nationale de la Recherche through the STILISM project (ANR-12-BS05-0016-02) and from BMBF through the Erasmus-F project (grant number 05 A12BA1). P.P. is supported by Ciencia 2008 Contract, funded by FCT/MCTES (Portugal) and POPH/FSE (EC), and J.M.G. by a Post-Doctoral grant, funded by FCT/MCTES (Portugal) and POPH/FSE (EC). P.P., and J.M.G. acknowledge support by the Fundação para a Ciência e a Tecnologia (FCT) under project FCOMP-01-0124-FEDER-029170 (Reference FCT PTDC/FIS-AST/3214/2012), funded by FCTMEC (PIDDAC) and FEDER (COMPETE)
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- 2015
13. The SAMI Galaxy Survey: satellite galaxies undergo little structural change during their quenching phase.
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Cortese, L, van de Sande, J, Lagos, C P, Catinella, B, Davies, L J M, Croom, S M, Brough, S, Bryant, J J, Lawrence, J S, Owers, M S, Richards, S N, Sweet, S M, and Bland-Hawthorn, J
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GALAXIES ,ARTIFICIAL satellites ,GALACTIC evolution ,STELLAR mass ,STAR formation - Abstract
At fixed stellar mass, satellite galaxies show higher passive fractions than centrals, suggesting that environment is directly quenching their star formation. Here, we investigate whether satellite quenching is accompanied by changes in stellar spin (quantified by the ratio of the rotational to dispersion velocity V /σ) for a sample of massive (M
* > 1010 M⊙ ) satellite galaxies extracted from the Sydney-AAO Multi-object Integral field spectrograph (SAMI) Galaxy Survey. These systems are carefully matched to a control sample of main sequence, high V /σ central galaxies. As expected, at fixed stellar mass and ellipticity, satellites have lower star formation rate (SFR) and spin than the control centrals. However, most of the difference is in SFR, whereas the spin decreases significantly only for satellites that have already reached the red sequence. We perform a similar analysis for galaxies in the Evolution and Assembly of GaLaxies and their Environments (EAGLE) hydrodynamical simulation and recover differences in both SFR and spin similar to those observed in SAMI. However, when EAGLE satellites are matched to their true central progenitors, the change in spin is further reduced and galaxies mainly show a decrease in SFR during their satellite phase. The difference in spin observed between satellites and centrals at z ∼ 0 is primarily due to the fact that satellites do not grow their angular momentum as fast as centrals after accreting into bigger haloes, not to a reduction of V /σ due to environmental effects. Our findings highlight the effect of progenitor bias in our understanding of galaxy transformation and they suggest that satellites undergo little structural change before and during their quenching phase. [ABSTRACT FROM AUTHOR]- Published
- 2019
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14. The SAMI galaxy survey: exploring the gas-phase mass–metallicity relation.
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Sánchez, S F, Barrera-Ballesteros, J K, López-Cobá, C, Brough, S, Bryant, J J, Bland-Hawthorn, J, Croom, S M, van de Sande, J, Cortese, L, Goodwin, M, Lawrence, J S, López-Sánchez, A R, Sweet, S M, Owers, M S, Richards, S N, Walcher, C J, and Team, SAMI
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INTEGRAL field spectroscopy - Abstract
We present a detailed exploration of the stellar mass versus gas-phase metallicity relation (MZR) using integral field spectroscopy data obtained from ∼1000 galaxies observed by the SAMI galaxy survey. These spatially resolved spectroscopic data allow us to determine the metallicity within the same physical scale (R
eff ) for different calibrators. The shape of the MZ relations is very similar between the different calibrators, while there are large offsets in the absolute values of the abundances. We confirm our previous results derived using the spatially resolved data provided by the CALIFA and MaNGA surveys: (1) we do not find any significant secondary relation of the MZR with either the star formation rate (SFR) or the specific SFR (SFR/ M* ) for any of the calibrators used in this study, based on the analysis of the individual residuals; (2) if there is a dependence with the SFR, it is weaker than the reported one (rc ∼ −0.3), it is confined to the low-mass regime (M* < 109 M⊙ ) or high-SFR regimes, and it does not produce any significant improvement in the description of the average population of galaxies. The aparent disagreement with published results based on single-fibre spectroscopic data could be due to (i) the interpretation of the secondary relation itself; (ii) the lower number of objects sampled at the low-mass regime by the current study; or (iii) the presence of extreme star-forming galaxies that drive the secondary relation in previous results. [ABSTRACT FROM AUTHOR]- Published
- 2019
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15. Galaxy and Mass Assembly (GAMA): environmental quenching of centrals and satellites in groups.
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Davies, L J M, Robotham, A S G, Lagos, C del P, Driver, S P, Stevens, A R H, Bahé, Y M, Alpaslan, M, Bremer, M N, Brown, M J I, Brough, S, Bland-Hawthorn, J, Cortese, L, Elahi, P, Grootes, M W, Holwerda, B W, Ludlow, A D, McGee, S, Owers, M, and Phillipps, S
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GALAXIES ,STAR formation ,STELLAR evolution ,STAR clusters ,ARTIFICIAL satellites - Abstract
Recently a number of studies have found a similarity between the passive fraction of central and satellite galaxies when controlled for both stellar and halo mass. These results suggest that the quenching processes that affect galaxies are largely agnostic to central/satellite status, which contradicts the traditional picture of increased satellite quenching via environmental processes such as stripping, strangulation, and starvation. Here we explore this further using the Galaxy And Mass Assembly (GAMA) survey, which extends to ∼2 dex lower in stellar mass than SDSS, is more complete for closely separated galaxies (≳95 per cent compared to ≳70 per cent), and identifies lower-halo-mass groups outside of the very local Universe (M
halo ∼ 1012 M⊙ at 0.1 < |$z$| < 0.2). As far as possible we aim to replicate the selections, completeness corrections, and central/satellite division of one of the previous studies but find clear differences between passive fractions of centrals and satellites. We also find that our passive fractions increase with both halo-to-satellite mass ratio and central-to-second rank mass ratio. This suggests that quenching is more efficient in satellites that are low-mass for their halo (i.e. at high halo-to-satellite mass ratio in comparison to low halo-to-satellite mass ratio) and are more likely to be passive in older groups – forming a consistent picture of environmental quenching of satellites. We then discuss potential explanations for the previously observed similarity, such as dependence on the group-finding method. [ABSTRACT FROM AUTHOR]- Published
- 2019
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16. SAMI Galaxy Survey: observing the environmental quenching of star formation in GAMA groups.
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Schaefer, A L, Croom, S M, Scott, N, Brough, S, Allen, J T, Bekki, K, Bland-Hawthorn, J, Bloom, J V, Bryant, J J, Cortese, L, Davies, L J M, Federrath, C, Fogarty, L M R, Green, A W, Groves, B, Hopkins, A M, Konstantopoulos, I S, López-Sánchez, A R, Lawrence, J S, and McElroy, R E
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STAR formation ,GALACTIC evolution ,STELLAR mass ,RADIAL distribution function ,DENSITY of stars - Abstract
We explore the radial distribution of star formation in galaxies in the SAMI Galaxy Survey as a function of their Local Group environment. Using a sample of galaxies in groups (with halo masses less than |$\simeq 10^{14} \, \mathrm{M_{\odot }}$|) from the Galaxy And Mass Assembly Survey, we find signatures of environmental quenching in high-mass groups (|$M_{\mathrm{ G}}\, \gt\, 10^{12.5} \, \mathrm{M_{\odot }}$|). The mean integrated specific star formation rate (sSFR) of star-forming galaxies in high-mass groups is lower than for galaxies in low-mass groups or those that are ungrouped, with |$\Delta \log (\mathrm{ sSFR}/\mathrm{yr^{-1}}) \,=\, 0.45 \pm 0.07$|. This difference is seen at all galaxy stellar masses. In high-mass groups, star-forming galaxies more massive than |$M_{*} \sim 10^{10} \, \mathrm{M_{\odot }}$| have centrally concentrated star formation. These galaxies also lie below the star formation main sequence, which suggests they may be undergoing outside-in quenching. Lower mass galaxies in high-mass groups do not show evidence of concentrated star formation. In groups less massive than |$M_{\mathrm{ G}} = 10^{12.5} \, \mathrm{M_{\odot }}$|, we do not observe these trends. In this regime, we find a modest correlation between centrally concentrated star formation and an enhancement in the total star formation rate, consistent with triggered star formation in these galaxies. [ABSTRACT FROM AUTHOR]
- Published
- 2019
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17. The SAMI Galaxy Survey: stellar and gas misalignments and the origin of gas in nearby galaxies.
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Bryant, J J, Croom, S M, van de Sande, J, Scott, N, Fogarty, L M R, Bland-Hawthorn, J, Bloom, J V, Taylor, E N, Brough, S, Robotham, A, Cortese, L, Couch, W, Owers, M S, Medling, A M, Federrath, C, Bekki, K, Richards, S N, Lawrence, J S, and Konstantopoulos, I S
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GALACTIC evolution ,EVOLUTIONARY theories ,SPECTRAL imaging ,SPECTROGRAPHS ,GALACTIC dynamics ,KINEMATICS - Abstract
Misalignment of gas and stellar rotation in galaxies can give clues to the origin and processing of accreted gas. Integral field spectroscopic observations of 1213 galaxies from the Sydney-AAO Multi-object Integral field spectrograph (SAMI) Galaxy Survey show that 11 per cent of galaxies with fitted gas and stellar rotation are misaligned by more than 30° in both field/group and cluster environments. Using SAMI morphological classifications and Sérsic indices, the misalignment fraction is 45 ± 6 per cent in early-type galaxies (ETGs), but only 5 ± 1 per cent in late-type galaxies (LTGs). The distribution of position angle offsets is used to test the physical drivers of this difference. Slower dynamical settling time of the gas in elliptical stellar mass distributions accounts for a small increase in misalignment in early-type galaxies. However, gravitational dynamical settling time is insufficient to fully explain the observed differences between ETGs and LTGs in the distributions of the gas/stellar position angle offsets. LTGs have primarily accreted gas close to aligned rather than settled from misaligned based on analysis of the skewed distribution of PA offsets compared to a dynamical settling model. Local environment density is less important in setting the misalignment fractions than morphology, suggesting that mergers are not the main source of accreted gas in these discs. Cluster environments are found to have gas misalignment driven primarily by cluster processes not by gas accretion. [ABSTRACT FROM AUTHOR]
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- 2019
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18. PKS B1740-517: an ALMA view of the cold gas feeding a distant interacting young radio galaxy.
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Allison, J R, Mahony, E K, Moss, V A, Sadler, E M, Whiting, M T, Allison, R F, Bland-Hawthorn, J, Curran, S J, Emonts, B H C, Lagos, C D P, Morganti, R, Tremblay, G, Zwaan, M, Anderson, C S, Bunton, J D, and Voronkov, M A
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RADIO galaxies ,COLD gases ,COSMIC dust ,REDSHIFT ,MOLECULAR absorption spectra ,SPACE debris - Abstract
Cold neutral gas is a key ingredient for growing the stellar and central black hole mass in galaxies throughout cosmic history. We have used the Atacama Large Millimetre Array to detect a rare example of redshifted
12 CO (2–1) absorption in PKS B1740–517, a young (t ∼ 1.6 × 103 yr) and luminous (|$L_{\rm 5\, GHz} \approx 6.6 \times 10^{43}$| erg s−1 ) radio galaxy at |$z$| = 0.44 that is undergoing a tidal interaction with at least one lower mass companion. The coincident H i 21-cm and molecular absorption have very similar line profiles and reveal a reservoir of cold gas (Mgas ∼ 107 −108 M⊙ ), likely distributed in a disc or ring within a few kiloparsecs of the nucleus. A separate H i component is kinematically distinct and has a very narrow line width (Δ |$v$|FWHM ≲ 5 km s−1 ), consistent with a single diffuse cloud of cold (Tk ∼ 100 K) atomic gas. The12 CO (2–1) absorption is not associated with this component, which suggests that the cloud is either much smaller than 100 pc along our sight line and/or located in low-metallicity gas that was possibly tidally stripped from the companion. We argue that the gas reservoir in PKS B1740–517 may have accreted on to the host galaxy ∼ 50 Myr before the young radio AGN was triggered, but has only recently reached the nucleus. This is consistent with the paradigm that powerful luminous radio galaxies are triggered by minor mergers and interactions with low-mass satellites and represent a brief, possibly recurrent, active phase in the life cycle of massive early-type galaxies. [ABSTRACT FROM AUTHOR]- Published
- 2019
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19. Mass-metallicity relation explored with CALIFA I. Is there a dependence on the star-formation rate?
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Sanchez, S. F., Rosales-Ortega, F. F., Jungwiert, B., Iglesias-Paramo1, J., Vilchez, J. M., Marino, R. A., Walcher, C. J., Husemann, B., Mast, D., Monreal-Ibero, A., Fernandes, R. Cid, Perez, E., Delgado, R. Gonzalez, Garcia-Benito, R., Galbany, L., van de Ven, G., Jahnke, K., Flores, H., Bland-Hawthorn, J., Lopez-Sánchez, A. R., Stanishev, V., Miralles-Caballero, D., Diaz, A. I., Sanchez-Blazquez, P., Molla, M., Gallazzi1, A., Papaderos, P., Gomes, J. M., Gruel, N., Pérez, I., Ruiz-Lara, T., Florido, E., de Lorenzo-Cáceres, A., Mendez-Abreu, J., Kehrig, C., Roth, M. M., Ziegler, B., Alves, J., Wisotzki, L., Kupko, D., Quirrenbach, A., Bomans, D., and collaboration, The CALIFA
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Astrofísica ,Galaxies: fundamental parameters ,Cosmology and Nongalactic Astrophysics (astro-ph.CO) ,Stellar mass ,Metallicity ,structure [Galaxies] ,FOS: Physical sciences ,Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,01 natural sciences ,Spectral line ,evolution [Galaxy] ,Galaxies: structure ,0103 physical sciences ,ISM [Galaxies] ,Astrophysics::Solar and Stellar Astrophysics ,10. No inequality ,010303 astronomy & astrophysics ,Astrophysics::Galaxy Astrophysics ,Physics ,spiral [Galaxies] ,010308 nuclear & particles physics ,Star formation ,1. No poverty ,Astrophysics::Instrumentation and Methods for Astrophysics ,fundamental parameters [Galaxy] ,Galaxies: evolution ,Sigma ,Física ,abundances [Galaxy] ,Astronomy and Astrophysics ,evolution [Galaxies] ,Galaxy ,Accretion (astrophysics) ,Astronomía ,Galaxies: ISM ,Cover (topology) ,Space and Planetary Science ,fundamental parameters [Galaxies] ,Galaxy: abundances ,Galaxies: spiral ,Astrophysics - Cosmology and Nongalactic Astrophysics - Abstract
We studied the global and local M-Z relation based on the first data available from the CALIFA survey (150 galaxies). This survey provides integral field spectroscopy of the complete optical extent of each galaxy (up to 2−3 effective radii), with a resolution high enough to separate individual Hii regions and/or aggregations. About 3000 individual Hii regions have been detected. The spectra cover the wavelength range between [OII]3727 and [SII]6731, with a sufficient signal-to-noise ratio to derive the oxygen abundance and star-formation rate associated with each region. In addition, we computed the integrated and spatially resolved stellar masses (and surface densities) based on SDSS photometric data. We explore the relations between the stellar mass, oxygen abundance and star-formation rate using this dataset. We derive a tight relation between the integrated stellar mass and the gas-phase abundance, with a dispersion lower than the one already reported in the literature (σΔlog (O/H) = 0.07 dex). Indeed, this dispersion is only slightly higher than the typical error derived for our oxygen abundances. However, we found no secondary relation with the star-formation rate other than the one induced by the primary relation of this quantity with the stellar mass. The analysis for our sample of ∼3000 individual Hii regions confirms (i) a local mass-metallicity relation and (ii) the lack of a secondary relation with the star-formation rate. The same analysis was performed with similar results for the specific star-formation rate. Our results agree with the scenario in which gas recycling in galaxies, both locally and globally, is much faster than other typical timescales, such like that of gas accretion by inflow and/or metal loss due to outflows. In essence, late-type/disk-dominated galaxies seem to be in a quasi-steady situation, with a behavior similar to the one expected from an instantaneous recycling/closed-box model., Nacional de Investigación y Desarrollo funding programs of the Spanish Ministerio de Ciencia e Innovación AYA2010-22111-C03-03 AYA2010-10904E, Ramon y Cajal project of the spanish Ministerio de Economía y Competitividad RyC-2011-07590, Academy of Sciences of the Czech Republic (ASCR Internal support program of international cooperation projects-PIPPMS) M100031241 M100031201, Czech Republic program for the long-term development of the research institution RVO67985815, Plan Nacional de Investigación y Desarrollo funding program AYA2010-15081, Consejo Nacional de Ciencia y Tecnología (CONACyT), Spanish grant AYA2010-15169, Junta de Andalucía TIC114, Excellence Project P08-TIC-03531, Consejo Superior de Investigaciones Científicas (CSIC), Junta para la Ampliación de Estudios, European Social Fund (ESF), spanish programme of International Campus of Excellence Moncloa, Spanish PNAYA AYA2010-21887, Spanish Government CSD2006-00070 AYA2012-38491-C02-02, Autonomic Government of Andalusia P08-TIC-4075 TIC-126, Ciencia, Portuguese Foundation for Science and Technology, European Commission European Commission Joint Research Centre European Social Fund (ESF), Portuguese Foundation for Science and Technology SFRH/BPD/66958/2009, National Science Foundation (NSF)
- Published
- 2013
20. The SAMI Galaxy Survey: gas content and interaction as the drivers of kinematic asymmetry.
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Bloom, J. V., Croom, S. M., Bryant, J. J., Schaefer, A. L., Bland-Hawthorn, J., Brough, S., Callingham, J., Cortese, L., Federrath, C., Scott, N., van de Sande, J., D'Eugenio, F., Sweet, S., Tonini, C., Allen, J. T., Goodwin, M., Green, A. W., Konstantopoulos, I. S., Lawrence, J., and Lorente, N.
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DWARF galaxies ,INTEGRAL field spectroscopy ,ASYMMETRY (Chemistry) ,KINEMATICS ,STELLAR mass ,FLOW velocity - Abstract
In order to determine the causes of kinematic asymmetry in the Hα gas in the SAMI (Sydney- AAO Multi-object IFS) Galaxy Survey sample, we investigate the comparative influences of environment and intrinsic properties of galaxies on perturbation. We use spatially resolved Hα velocity fields from the SAMI Galaxy Survey to quantify kinematic asymmetry (...) in nearby galaxies and environmental and stellar mass data from the Galaxy And Mass Assembly survey. We find that local environment, measured as distance to nearest neighbour, is inversely correlated with kinematic asymmetry for galaxies with log (M
* /M⊙ ) > 10.0, but there is no significant correlation for galaxies with log (M* /M⊙ ) < 10.0. Moreover, lowmass galaxies [log (M* /M⊙ ) < 9.0] have greater kinematic asymmetry at all separations, suggesting a different physical source of asymmetry is important in low-mass galaxies. We propose that secular effects derived from gas fraction and gas mass may be the primary causes of asymmetry in low-mass galaxies. High gas fraction is linked to high σm /V (where σm is Hα velocity dispersion and V the rotation velocity), which is strongly correlated with ..., and galaxies with log (M* /M⊙ ) < 9.0 have offset ... from the rest of the sample. Further, asymmetry as a fraction of dispersion decreases for galaxies with log (M* /M⊙ ) < 9.0. Gas mass and asymmetry are also inversely correlated in our sample. We propose that low gas masses in dwarf galaxies may lead to asymmetric distribution of gas clouds, leading to increased relative turbulence. [ABSTRACT FROM AUTHOR]- Published
- 2018
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21. The KMOS Redshift One Spectroscopic Survey (KROSS): the origin of disc turbulence in z≈1 star-forming galaxies.
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Johnson, H. L., Harrison, C. M., Swinbank, A. M., Tiley, A. L., Stott, J. P., Bower, R. G., Smail, Ian, Bunker, A. J., Sobral, D., Turner, O. J., Best, P., Bureau, M., Cirasuolo, M., Jarvis, M. J., Magdis, G., Sharples, R. M., Bland-Hawthorn, J., Catinella, B., Cortese, L., and Croom, S. M.
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REDSHIFT ,DISK galaxies ,STAR formation ,STELLAR evolution ,GALAXY formation - Abstract
We analyse the velocity dispersion properties of 472 z ∼ 0.9 star-forming galaxies observed as part of the KMOS Redshift One Spectroscopic Survey (KROSS). The majority of this sample is rotationally dominated (83 ± 5 per cent with v
C /σ0 > 1) but also dynamically hot and highly turbulent. After correcting for beam smearing effects, the median intrinsic velocity dispersion for the final sample is σ0 = 43.2 ± 0.8 km s−1 with a rotational velocity to dispersion ratio of vC /σ0 = 2.6 ± 0.1. To explore the relationship between velocity dispersion, stellar mass, star formation rate, and redshift, we combine KROSS with data from the SAMI survey (z ∼ 0.05) and an intermediate redshift MUSE sample (z ∼ 0.5). Whilst there is, at most, a weak trend between velocity dispersion and stellar mass, at fixed mass there is a strong increase with redshift. At all redshifts, galaxies appear to follow the same weak trend of increasing velocity dispersion with star formation rate. Our results are consistent with an evolution of galaxy dynamics driven by discs that are more gas rich, and increasingly gravitationally unstable, as a function of increasing redshift. Finally, we test two analytic models that predict turbulence is driven by either gravitational instabilities or stellar feedback. Both provide an adequate description of the data, and further observations are required to rule out either model. [ABSTRACT FROM AUTHOR]- Published
- 2018
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22. Galaxy and mass assembly (GAMA): the consistency of GAMA and WISE derived mass-to-light ratios.
- Author
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Kettlety, T., Hesling, J., Phillipps, S., Bremer, M. N., Cluver, M. E., Taylor, E. N., Bland-Hawthorn, J., Brough, S., De Propris, R., Driver, S. P., Holwerda, B. W., Kelvin, L. S., Sutherland, W., and Wright, A. H.
- Subjects
STELLAR populations ,SPECTRAL energy distribution ,WAVELENGTHS ,GALAXIES ,REDSHIFT - Abstract
Recent work has suggested that mid-IR wavelengths are optimal for estimating the mass-tolight ratios of stellar populations and hence the stellar masses of galaxies. We compare stellar masses deduced from spectral energy distribution (SED) models, fitted to multiwavelength optical-NIR photometry, to luminosities derived from WISE photometry in the W1 and W2 bands at 3.6 and 4.5 μm for non-star forming galaxies. The SED-derived masses for a carefully selected sample of low-redshift (z≤0.15) passive galaxies agree with the prediction from stellar population synthesis models such that M
* /LW1 ≃0.6 for all such galaxies, independent of other stellar population parameters. The small scatter between masses predicted from the optical SED and from the WISE measurements implies that random errors (as opposed to systematic ones such as the use of different initial mass functions) are smaller than previous, deliberately conservative, estimates for the SED fits. This test is subtly different from simultaneously fitting at a wide range of optical and mid-IR wavelengths, which may just generate a compromised fit: we are directly checking that the best-fitting model to the optical data generates an SED whose M* /LW1 is also consistent with separate mid-IR data. We confirm that for passive low-redshift galaxies a fixed M* /LW1 = 0.65 can generate masses at least as accurate as those obtained from more complex methods. Going beyond the mean value, in agreement with expectations from the models, we see a modest change in M* /LW1 with SED fitted stellar population age but an insignificant one with metallicity. [ABSTRACT FROM AUTHOR]- Published
- 2018
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23. The SAMI Galaxy Survey: understanding observations of large-scale outflows at low redshift with EAGLE simulations.
- Author
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Tescari, E., Cortese, L., Power, C., Wyithe, J. S. B., Ho, I.-T., Crain, R. A., Bland-Hawthorn, J., Croom, S. M., Kewley, L. J., Schaye, J., Bower, R. G., Theuns, T., Schaller, M., Barnes, L., Brough, S., Bryant, J. J., Goodwin, M., Gunawardhana, M. L. P., Lawrence, J. S., and Leslie, S. K.
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REDSHIFT ,STELLAR mass ,VELOCITY ,BIPOLAR outflows (Astrophysics) ,STARBURSTS ,GALACTIC windows ,SIMULATION methods & models - Abstract
This work presents a study of galactic outflows driven by stellar feedback. We extract mainsequence disc galaxies with stellar mass 109 ≤ M
* / M ≤ 5.7 × 1010 at redshift z = 0 from the highest resolution cosmological simulation of the Evolution and Assembly of GaLaxies and their Environments (EAGLE) set. Synthetic gas rotation velocity and velocity dispersion (σ) maps are created and compared to observations of disc galaxies obtained with the Sydney-AAO (Australian Astronomical Observatory) Multi-object Integral field spectrograph (SAMI), where σ- values greater than 150 km s−1 are most naturally explained by bipolar outflows powered by starburst activity. We find that the extension of the simulated edge-on (pixelated) velocity dispersion probability distribution depends on stellar mass and star formation rate surface density (ΣSFR), with low-MM* /low- ΣSFR galaxies showing a narrow peak at low σ (~30 km s−1 ) and more active, high-MM* /high-ΣSFR galaxies reachingσ >150 km s−1 . Although supernova-driven galactic winds in the EAGLE simulations may not entrain enough gas with T <105 K compared to observed galaxies, we find that gas temperature is a good proxy for the presence of outflows. There is a direct correlation between the thermal state of the gas and its state of motion as described by the σ-distribution. The following equivalence relations hold in EAGLE: (i) low- σ peak ⇔disc of the galaxy ⇔gas with T <105 K; (ii) high- σ tail ⇔galactic winds ⇔gas with T ≥105 K. [ABSTRACT FROM AUTHOR]- Published
- 2018
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24. Galaxy And Mass Assembly (GAMA): The mechanisms for quiescent galaxy formation at z < 1.
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Rowlands, K., Wild, V., Bourne, N., Bremer, M., Brough, S., Driver, S. P., Hopkins, A. M., Owers, M. S., Phillipps, S., Pimbblet, K., Sansom, A. E., Wang, L., Alpaslan, M., Bland-Hawthorn, J., Colless, M., Holwerda, B. W., and Taylor, E. N.
- Subjects
GALACTIC evolution ,GALAXY formation ,GALAXIES ,STELLAR luminosity function ,STARBURSTS ,STAR formation - Abstract
One key problem in astrophysics is understanding how and why galaxies switch off their star formation, building the quiescent population that we observe in the local Universe. From the Galaxy And Mass Assembly and VIsible MultiObject Spectrograph Public Extragalactic Redshift surveys, we use spectroscopic indices to select quiescent and candidate transition galaxies.We identify potentially rapidly transitioning post-starburst (PSB) galaxies and slower transitioning green-valley galaxies. Over the last 8Gyr, the quiescent population has grown more slowly in number density at high masses (M* > 10
11 M☉ ) than at intermediate masses (M* > 1010.6 M☉ ). There is evolution in both the PSB and green-valley stellar mass functions, consistent with higher mass galaxies quenching at earlier cosmic times.At intermediatemasses (M* > 1010.6 M☉ ), we find a green-valley transition time-scale of 2.6 Gyr. Alternatively, at z ~ 0.7, the entire growth rate could be explained by fast-quenching PSB galaxies, with a visibility time-scale of 0.5 Gyr. At lower redshift, the number density of PSBs is so low that an unphysically short visibility window would be required for them to contribute significantly to the quiescent population growth. The importance of the fast-quenching route may rapidly diminish at z < 1. However, at high masses (M* > 1011 M☉ ), there is tension between the large number of candidate transition galaxies compared to the slow growth of the quiescent population. This could be resolved if not all high-mass PSB and green-valley galaxies are transitioning from star forming to quiescent, for example if they rejuvenate out of the quiescent population following the accretion of gas and triggering of star formation, or if they fail to completely quench their star formation. [ABSTRACT FROM AUTHOR]- Published
- 2018
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25. The SAMI Galaxy Survey: the low-redshift stellar mass Tully-Fisher relation.
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Bloom, J. V., Croom, S. M., Bryant, J. J., Callingham, J. R., Schaefer, A. L., Cortese, L., Hopkins, A. M., D'Eugenio, F., Scott, N., Glazebrook, K., Tonini, C., McElroy, R. E., Clark, H. A., Catinella, B., Allen, J. T., Bland-Hawthorn, J., Goodwin, M., Green, A. W., Konstantopoulos, I. S., and Lawrence, J.
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GALACTIC evolution ,GALACTIC redshift ,STELLAR mass ,SPECTRAL imaging ,INTEGRAL field spectroscopy - Abstract
We investigate the Tully-Fisher relation (TFR) for a morphologically and kinematically diverse sample of galaxies from the Sydney-AAO Multi-object Integral field spectrograph (SAMI) Galaxy Survey using two-dimensional spatially resolved Hα velocity maps and find a welldefined relation across the stellar mass range of 8.0 < log (M
* /M☉ ) < 11.5. We use an adaptation of kinemetry to parametrize the kinematic Hα asymmetry of all galaxies in the sample, and find a correlation between scatter (i.e. residuals off the TFR) and asymmetry. This effect is pronounced at low stellar mass, corresponding to the inverse relationship between stellar mass and kinematic asymmetry found in previous work. For galaxies with log (M* /M☉ ) < 9.5, 25 ± 3 per cent are scattered below the root mean square (RMS) of the TFR, whereas for galaxies with log (M* /M☉ ) > 9.5 the fraction is 10 ± 1 per cent. We use 'simulated slits' to directly compare our results with those from long slit spectroscopy and find that aligning slits with the photometric, rather than the kinematic, position angle, increases global scatter below the TFR. Further, kinematic asymmetry is correlated with misalignment between the photometric and kinematic position angles. This work demonstrates the value of 2D spatially resolved kinematics for accurate TFR studies; integral field spectroscopy reduces the underestimation of rotation velocity that can occur from slit positioning off the kinematic axis. [ABSTRACT FROM AUTHOR]- Published
- 2017
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26. The SAMI Galaxy Survey: disc–halo interactions in radio-selected star-forming galaxies.
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Leslie, K., Bryant,, J. J., Ho, I.-T., Sadler, E. M., Medling, A. M., Groves, B., Kewley, L. J., Bland-Hawthorn, J., Croom, S. M., Wong, O. I., Brough, S., Tescari, E., Sweet, S. M., Sharp, R., Green, A. W., López-Sánchez, Á. R., Allen, J. T., Fogarty, L. M. R., Goodwin, M., and Lawrence, J. S.
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STAR formation ,GALAXIES ,SOLAR radio emission ,STELLAR luminosity function ,COSMIC rays - Abstract
In this paper, we compare the radio emission at 1.4 GHz with optical outflow signatures of edgeon galaxies. We report observations of six edge-on star-forming galaxies in the Sydney-AAO Multiobject Integral-field spectrograph Galaxy Survey with 1.4 GHz luminosities >1 × 10
21 WHz-1 . Extended minor axis optical emission is detected with enhanced [N II]/H α line ratios and velocity dispersions consistent with galactic winds in three of six galaxies. These galaxies may host outflows driven by a combination of thermal and cosmic ray processes. We find that galaxies with the strongest wind signatures have extended radio morphologies. Our results form a baseline for understanding the driving mechanisms of galactic winds. [ABSTRACT FROM AUTHOR]- Published
- 2017
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27. Galaxy And Mass Assembly (GAMA): Galaxy environments and star formation rate variations
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Wijesinghe, D.B., Hopkins, A.M., Brough, S., Taylor, E.N., Norberg, P., Bauer, A., Brown, M.J.I., Cameron, E., Conselice, C.J., Croom, S., Driver, S., Grootes, M.W., Jones, D.H., Kelvin, L., Loveday, J., Pimbblet, K.A., Popescu, C.C., Prescott, M., Sharp, R., Baldry, I., Sadler, E.M., Liske, J., Robotham, A.S.G., Bamford, S., Bland-Hawthorn, J., Gunawardhana, M., Meyer, M., Parkinson, H., Drinkwater, M.J., Peacock, J., and Tuffs, R.
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Galaxies: general ,Galaxies: star formation ,evolution ,Galaxies: formation ,Galaxies: star formation [Galaxies] ,Galaxies: evolution ,general [Galaxies] ,Astrophysics::Cosmology and Extragalactic Astrophysics ,evolution [Galaxies] ,star formation. [Galaxies] ,formation [Galaxies] ,Astrophysics::Galaxy Astrophysics - Abstract
Monthly Notices of the Royal Astronomical Society, 423 (4), ISSN:0035-8711, ISSN:1365-2966, ISSN:1365-8711
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- 2012
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28. GAMA/H-ATLAS: the ultraviolet spectral slope and obscuration in galaxies
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Wijesinghe, D.B., Da Cunha, E., Hopkins, A.M., Dunne, L., Sharp, R., Gunawardhana, M., Brough, S., Sadler, E.M., Driver, S., Baldry, I., Bamford, S., Liske, J., Loveday, J., Norberg, P., Peacock, J., Popescu, C.C., Tuffs, R., Andrae, E., Auld, R., Baes, M., Bland-Hawthorn, J., Buttiglione, S., Cava, A., Cameron, E., Conselice, C.J., Cooray, A., Croom, S., Dariush, A., DeZotti, G., Dye, S., Eales, S., Frenk, C., Fritz, J., Hill, D., Hopwood, R., Ibar, E., Ivison, R., Jarvis, M., Jones, D.H., Kampen, E. van, Kelvin, L., Kuijken, K.H., Maddox, S.J., Madore, B., Michalowski, M.J., Nichol, B., Parkinson, H., Pascale, E., Pimbblet, K.A., Pohlen, M., Prescott, M., Rhodighiero, G., Robotham, A.S.G., Rigby, E.E., Seibert, M., Sergeant, S., Smith, D.J.B., Temi, P., Sutherland, W., Taylor, E., Thomas, D., and Werf, P.P. van der
- Subjects
Galaxies: evolution ,Galaxies: formation ,Galaxies: general ,Astronomy and Astrophysics ,Space and Planetary Science ,Cosmology and Gravitation ,Cosmology and Nongalactic Astrophysics (astro-ph.CO) ,Astrophysics::Solar and Stellar Astrophysics ,FOS: Physical sciences ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Astrophysics::Galaxy Astrophysics ,QB ,Astrophysics - Cosmology and Nongalactic Astrophysics - Abstract
We use multiwavelength data from the Galaxy And Mass Assembly (GAMA) and Herschel ATLAS (H-ATLAS) surveys to compare the relationship between various dust obscuration measures in galaxies. We explore the connections between the ultraviolet (UV) spectral slope, $\beta$, the Balmer decrement, and the far infrared (IR) to $150\,$nm far ultraviolet (FUV) luminosity ratio. We explore trends with galaxy mass, star formation rate (SFR) and redshift in order to identify possible systematics in these various measures. We reiterate the finding of other authors that there is a large scatter between the Balmer decrement and the $\beta$ parameter, and that $\beta$ may be poorly constrained when derived from only two broad passbands in the UV. We also emphasise that FUV derived SFRs, corrected for dust obscuration using $\beta$, will be overestimated unless a modified relation between $\beta$ and the attenuation factor is used. Even in the optimum case, the resulting SFRs have a significant scatter, well over an order of magnitude. While there is a stronger correlation between the IR to FUV luminosity ratio and $\beta$ parameter than with the Balmer decrement, neither of these correlations are particularly tight, and dust corrections based on $\beta$ for high redshift galaxy SFRs must be treated with caution. We conclude with a description of the extent to which the different obscuration measures are consistent with each other as well as the effects of including other galactic properties on these correlations., Comment: Accepted by MNRAS, 12 pages, 8 figures
- Published
- 2011
29. Galaxy and mass assembly (GAMA): dust obscuration in galaxies and their recent star formation histories
- Author
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Wijesinghe, D.B., Hopkins, A.M., Sharp, R., Gunawardhana, M., Brough, S., Sadler, E.M., Driver, S., Baldry, I., Bamford, S., Liske, J., Loveday, J., Norberg, P., Peacock, J., Popescu, C.C., Tuffs, R.J., Bland-Hawthorn, J., Cameron, E., Croom, S., Frenk, C., Hill, D., Jones, D.H., Kampen, E. van, Kelvin, L., Kuijken, K.H., Madore, B., Nichol, B., Parkinson, H., Pimbblet, K.A., Prescott, M., Robotham, A.S.G., Seibert, M., Simmat, E., Sutherland, W., Taylor, E., and Thomas, D.
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Galaxies: general ,Galaxies: fundamental parameters ,Cosmology and Nongalactic Astrophysics (astro-ph.CO) ,Galaxies: luminosity function, mass function ,FOS: Physical sciences ,Galaxies: evolution ,evolution ,Galaxies: formation ,Galaxies: luminosity function, mass function [Galaxies] ,Astrophysics - Cosmology and Nongalactic Astrophysics - Abstract
Monthly Notices of the Royal Astronomical Society, 410 (4), ISSN:0035-8711, ISSN:1365-2966, ISSN:1365-8711
- Published
- 2011
30. Galaxy And Mass Assembly: the evolution of the cosmic spectral energy distribution from z = 1 to z = 0.
- Author
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Andrews, S. K., Davies, L. J. M., Kafle, P. R., Robotham, A. S. G., Vinsen, K., Driver, S. P., Wright, A. H., Hopkins, A. M., Kelvin, L. S., Loveday, J., Wilkins, S., Bland-Hawthorn, J., Bourne, N., Bremer, M., Phillipps, S., da Cunha, E., Drinkwater, M., and Holwerda, B.
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COSMIC ray energy spectra ,GALAXIES ,METAPHYSICAL cosmology ,COSMIC background radiation - Abstract
We present the evolution of the cosmic spectral energy distribution (CSED) from z = 1 zto 0. Our CSEDs originate from stacking individual spectral energy distribution (SED) fits based on panchromatic photometry from the Galaxy And Mass Assembly (GAMA) and COSMOS data sets in 10 redshift intervals with completeness corrections applied. Below z = 0.45, we have credible SED fits from 100 nm to 1 mm. Due to the relatively low sensitivity of the far-infrared data, our far-infrared CSEDs contain a mix of predicted and measured fluxes above z = 0.45. Our results include appropriate errors to highlight the impact of these corrections. We show that the bolometric energy output of the Universe has declined by a factor of roughly 4 - from 5.1 ± 1.0 at z ~ 1 to 1.3 ± 0.3 × 10
35 h70 W Mpc-3 at the current epoch. We show that this decrease is robust to cosmic sample variance, the SED modelling and other various types of error. Our CSEDs are also consistent with an increase in the mean age of stellar populations. We also show that dust attenuation has decreased over the same period, with the photon escape fraction at 150 nm increasing from 16 ± 3 at z ~ 1 to 24 ± 5 per cent at the current epoch, equivalent to a decrease in AFUV of 0.4 mag. Our CSEDs account for 68 ± 12 and 61 ± 13 per cent of the cosmic optical and infrared backgrounds, respectively, as defined from integrated galaxy counts and are consistent with previous estimates of the cosmic infrared background with redshift. [ABSTRACT FROM AUTHOR]- Published
- 2017
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31. Galaxy And Mass Assembly (GAMA): the galaxy stellar mass function to z = 0.1 from the r-band selected equatorial regions.
- Author
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Wright, A. H., Robotham, A. S. G., Driver, S. P., Alpaslan, M., Andrews, S. K., Baldry, I. K., Bland-Hawthorn, J., Brough, S., Brown, M. J. I., Colless, M., da Cunha, E., Davies, L. J. M., Graham, Alister W., Holwerda, B. W., Hopkins, A. M., Kafle, P. R., Kelvin, L. S., Loveday, J., Maddox, S. J., and Meyer, M. J.
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STELLAR mass ,GALACTIC redshift ,GALACTIC evolution ,STELLAR luminosity function - Abstract
We derive the low-redshift galaxy stellar mass function (GSMF), inclusive of dust corrections, for the equatorial Galaxy And Mass Assembly (GAMA) data set covering 180 deg
2 . We construct the mass function using a density-corrected maximum volume method, using masses corrected for the impact of optically thick and thin dust. We explore the galactic bivariate brightness plane (M* -μ), demonstrating that surface brightness effects do not systematically bias our mass function measurement above 107.5 M⊙ . The galaxy distribution in the M-μ plane appears well bounded, indicating that no substantial population of massive but diffuse or highly compact galaxies are systematically missed due to the GAMA selection criteria. The GSMF is fitted with a double Schechter function, with M* = 1010.78±0.01±0.20 M⊙ , ϕ*1 = (2.93 ± 0.40) × 10-3 h3 70 Mpc-3 , α1 = -0.62 ± 0.03 ± 0.15, ϕ*2 = (0.63 ± 0.10) × 10-3 h3 70 Mpc-3 and α2 = -1.50 ± 0.01 ± 0.15. We find the equivalent faint end slope as previously estimated using the GAMA-I sample, although we find a higher value of M⊙ . Using the full GAMA-II sample, we are able to fit the mass function to masses as low as 107.5 M⊙ , and assess limits to 106.5 M⊙ . Combining GAMA-II with data from G10-COSMOS, we are able to comment qualitatively on the shape of the GSMF down to masses as low as 106 M⊙ . Beyond the well-known upturn seen in the GSMF at 109.5 , the distribution appears to maintain a single power-law slope from 109 to 106.5 . We calculate the stellar mass density parameter given our best-estimate GSMF, finding Ω* = 1.66+0.24 -0.23 ± 0.97 h-1 70 × 10-3 , inclusive of random and systematic uncertainties. [ABSTRACT FROM AUTHOR]- Published
- 2017
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32. Towards a new classification of galaxies: principal component analysis of CALIFA circular velocity curves.
- Author
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Kalinova, V., Colombo, D., Rosolowsky, E., Kannan, R., Galbany, L., Garcóa-Benito, R., Delgado, R. González, Sánchez, S. F., Ruiz-Lara, T., Méndez-Abreu, J., Catalán-Torrecilla, C., Sánchez-Menguiano, L., de Lorenzo-Cáceres, A., Costantin, L., Florido, E., Kodaira, K., Marino, R. A., Läsker, R., and Bland-Hawthorn, J.
- Subjects
CLASSIFICATION of galaxies ,SURFACE brightness (Astronomy) ,PRINCIPAL components analysis ,STELLAR dynamics ,K-means clustering - Abstract
We present a galaxy classification system for 238 (E1.Sdm) CALIFA (Calar Alto Legacy Integral Field Area) galaxies based on the shapes and amplitudes of their circular velocity curves (CVCs). We infer the CVCs from the de-projected surface brightness of the galaxies, after scaling by a constant mass-to-light ratio based on stellar dynamics - solving axisymmetric Jeans equations via fitting the second velocity moment V
rms = √V² + σ² of the stellar kinematics. We use principal component analysis (PCA) applied to the CVC shapes to find characteristic features and use a k-means classifier to separate circular curves into classes. This objective classification method identifies four different classes, which we name slow-rising (SR), flat (FL), round-peaked (RP) and sharp-peaked (SP) circular curves. SR are typical for low-mass, late-type (Sb.Sdm), young, faint, metal-poor and disc-dominated galaxies. SP are typical for high-mass, early-type (E1-E7), old, bright, metal-rich and bulge-dominated galaxies. FL and RP appear presented by galaxies with intermediate mass, age, luminosity, metallicity, bulge-to-disc ratio and morphologies (E4-S0a, Sa-Sbc). The discrepancy mass factor, fd = 1 - M* /Mdyn , have the largest value for SR and SP classes (~ 74 per cent and ~ 71 per cent, respectively) in contrast to the FL and RP classes (with ~ 59 per cent and ~ 61 per cent, respectively). Circular curve classification presents an alternative to typical morphological classification and appears more tightly linked to galaxy evolution. [ABSTRACT FROM AUTHOR]- Published
- 2017
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- View/download PDF
33. The mass-metallicity relation revisited with CALIFA.
- Author
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Sánchez, S. F., Barrera-Ballesteros, J. K., Sánchez-Menguiano, L., Walcher, C. J., Marino, R. A., Galbany, L., Bland-Hawthorn, J., Cano-Díaz, M., García-Benito, R., López-Cobá, C., Zibetti, S., Vilchez, J. M., Igléias-Páramo, J., Kehrig, C., López Sáanchez, A. R., Duarte Puertas, S., and Ziegler, B.
- Subjects
METALLURGY ,INTEGRAL field spectroscopy ,METALLIC epitaxial layers ,SPECTRUM analysis ,SPECTROMETRY - Abstract
We present an updated version of the mass-metallicity (MZ) relation using integral field spectroscopy data obtained from 734 galaxies observed by the CALIFA survey. These unparalleled spatially resolved spectroscopic data allow us to determine the metallicity at the same physical scale (R
e ) for different calibrators. We obtain MZ relations with similar shapes for all calibrators, once the scalefactors among them are taken into account. We do not find any significant secondary relation of the MZ relation with either the star formation rate (SFR) or the specific SFR for any of the calibrators used in this study, based on the analysis of the residuals of the best-fitted relation. However, we do see a hint for an (s)SFR-dependent deviation of the MZ relation at low masses (M < 109.5 Mʘ), where our sample is not complete.We are thus unable to confirm the results by Mannucci et al. (2010), although we cannot exclude that this result is due to the differences in the analysed data sets. In contrast, our results are inconsistent with the results by Lara-López et al. (2010), and we can exclude the presence of an SFR-mass-oxygen abundance fundamental plane. These results agree with previous findings suggesting that either (1) the secondary relation with the SFR could be induced by an aperture effect in single fibre/aperture spectroscopic surveys, (2) it could be related to a local effect confined to the central regions of galaxies or (3) it is just restricted to the low-mass regime, or a combination of the three effects. [ABSTRACT FROM AUTHOR]- Published
- 2017
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34. Observational hints of radial migration in disc galaxies from CALIFA.
- Author
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Ruiz-Lara, T., Pérez, I., Florido, E., Sánchez-Blázquez, P., Méndez-Abreu, J., Sánchez-Menguiano, L., Sánchez, S. F., Lyubenova, M., Falcón-Barroso, J., van de Ven, G., Marino, R. A., de Lorenzo-Cáceres, A., Catalán-Torrecilla, C., Costantin, L., Bland-Hawthorn, J., Galbany, L., García-Benito, R., Husemann, B., Kehrig, C., and Márquez, I.
- Subjects
STARS ,GALAXIES ,STELLAR evolution ,INTEGRAL field spectroscopy ,ACCRETION (Astrophysics) - Abstract
Context. According to numerical simulations, stars are not always kept at their birth galactocentric distances but they have a tendency to migrate. The importance of this radial migration in shaping galactic light distributions is still unclear. However, if radial migration is indeed important, galaxies with different surface brightness (SB) profiles must display differences in their stellar population properties. Aims. We investigate the role of radial migration in the light distribution and radial stellar content by comparing the inner colour, age, and metallicity gradients for galaxies with different SB profiles. We define these inner parts, avoiding the bulge and bar regions and up to around three disc scale lengths (type I, pure exponential) or the break radius (type II, downbending; type III, upbending). Methods. We analysed 214 spiral galaxies from the CALIFA survey covering different SB profiles. We made use of GASP2D and SDSS data to characterise the light distribution and obtain colour profiles of these spiral galaxies. The stellar age and metallicity profiles were computed using a methodology based on full-spectrum fitting techniques (pPXF, GANDALF, and STECKMAP) to the Integral Field Spectroscopic CALIFA data. Results. The distributions of the colour, stellar age, and stellar metallicity gradients in the inner parts for galaxies displaying different SB profiles are unalike as suggested by Kolmogorov-Smirnov and Anderson-Darling tests. We find a trend in which type II galaxies show the steepest profiles of all, type III show the shallowest, and type I display an intermediate behaviour. Conclusions. These results are consistent with a scenario in which radial migration is more efficient for type III galaxies than for type I systems, where type II galaxies present the lowest radial migration efficiency. In such a scenario, radial migration mixes the stellar content, thereby flattening the radial stellar properties and shaping different SB profiles. However, in light of these results we cannot further quantify the importance of radial migration in shaping spiral galaxies, and other processes, such as recent star formation or satellite accretion, might play a role. [ABSTRACT FROM AUTHOR]
- Published
- 2017
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- View/download PDF
35. The SAMI Galaxy Survey: asymmetry in gas kinematics and its links to stellar mass and star formation.
- Author
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Bloom, J. V., Fogarty, L. M. R., Croom, S. M., Schaefer, A., Bryant, J. J., Cortese, L., Richards, S., Bland-Hawthorn, J., Ho, I.-T., Scott, N., Goldstein, G., Medling, A., Brough, S., Sweet, S. M., Cecil, G., López-Sánchez, A., Glazebrook, K., Parker, Q., Allen, J. T., and Goodwin, M.
- Subjects
GALACTIC evolution ,STAR formation ,KINEMATICS ,STELLAR mass ,SPECTROGRAPHS - Abstract
We study the properties of kinematically disturbed galaxies in the Sydney-AAO Multi-object Integral field spectrograph (SAMI) Galaxy Survey using a quantitative criterion, based on kinemetry (Krajnovic et al.). The approach, similar to the application of kinemetry by Shapiro et al., uses ionized gas kinematics, probed by H α emission. By this method, 23 ± 7 per cent of our 360-galaxy sub-sample of the SAMI Galaxy Survey are kinematically asymmetric. Visual classifications agree with our kinemetric results for 90 per cent of asymmetric and 95 per cent of normal galaxies. We find that stellar mass and kinematic asymmetry are inversely correlated and that kinematic asymmetry is both more frequent and stronger in low-mass galaxies. This builds on previous studies that found high fractions of kinematic asymmetry in low-mass galaxies using a variety of different methods. Concentration of star formation and kinematic disturbance are found to be correlated, confirming results found in previous work. This effect is stronger for high-mass galaxies (log(M
* ) > 10) and indicates that kinematic disturbance is linked to centrally concentrated star formation. Comparison of the inner (within 0.5Re ) and outer Hα equivalent widths of asymmetric and normal galaxies shows a small but significant increase in inner equivalent width for asymmetric galaxies. [ABSTRACT FROM AUTHOR]- Published
- 2017
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- View/download PDF
36. Galaxy And Mass Assembly (GAMA): the absence of stellar mass segregation in galaxy groups and consistent predictions from GALFORM and EAGLE simulations.
- Author
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Kafle, P. R., Robotham, A. S. G., del P. Lagos, C., Davies, L. J., Moffett, A. J., Driver, S. P., Andrews, S. K., Baldry, I. K., Bland-Hawthorn, J., Brough, S., Cortese, L., Drinkwater, M. J., Finnegan, R., Hopkins, A. M., and Loveday, J.
- Subjects
STELLAR mass ,HYDRODYNAMICS ,SIMULATION methods & models ,RADIAL distribution function - Abstract
We investigate the contentious issue of the presence, or lack thereof, of satellites mass segregation in galaxy groups using the Galaxy And Mass Assembly (GAMA) survey, the GALFORM semi-analytic, and the EAGLE cosmological hydrodynamical simulation catalogues of galaxy groups. We select groups with halo mass 12 ≤ log (M
halo /h-1 M⊙ ) < 14.5 and redshift z ≤ 0.32 and probe the radial distribution of stellar mass out to twice the group virial radius. All the samples are carefully constructed to be complete in stellar mass at each redshift range and efforts are made to regularize the analysis for all the data. Our study shows negligible mass segregation in galaxy group environments with absolute gradients of ~0.08 dex and also shows a lack of any redshift evolution. Moreover, we find that our results at least for the GAMA data are robust to different halo mass and group centre estimates. Furthermore, the EAGLE data allows us to probe much fainter luminosities (r-band magnitude of 22) as well as investigate the three-dimensional spatial distribution with intrinsic halo properties, beyond what the current observational data can offer. In both cases we find that the fainter EAGLE data show a very mild spatial mass segregation at z ≤ 0.22, which is again not apparent at higher redshift. Interestingly, our results are in contrast to some earlier findings using the Sloan Digital Sky Survey. We investigate the source of the disagreement and suggest that subtle differences between the group-finding algorithms could be the root cause. [ABSTRACT FROM AUTHOR]- Published
- 2016
- Full Text
- View/download PDF
37. The SAMI Galaxy Survey: the link between angular momentum and optical morphology.
- Author
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Cortese, L., R. Fogarty, L. M., Bekki, K., van de Sande, J., Couch, W., Catinella, B., Colless, M., Obreschkow, D., Taranu, D., Tescari, E., Barat, D., Bland-Hawthorn, J., Bloom, J., Bryant, J. J., Cluver, M., Croom, S. M., Drinkwater, M. J., d’Eugenio, F., Konstantopoulos, I. S., and Lopez-Sanchez, A.
- Subjects
INTEGRAL field spectroscopy ,ANGULAR momentum (Mechanics) ,STELLAR mass ,GALACTIC evolution ,KINEMATICS ,ASTRONOMICAL research - Abstract
We investigate the relationship between stellar and gas specific angular momentum j, stellar mass M
* and optical morphology for a sample of 488 galaxies extracted from the Sydney-AAO Multi-object Integral field Galaxy Survey. We find that j, measured within one effective radius, monotonically increases with M* and that, for M* > 109.5 M⊙ , the scatter in this relation strongly correlates with optical morphology (i.e. visual classification and Sérsic index). These findings confirm that massive galaxies of all types lie on a plane relating mass, angular momentum and stellar-light distribution, and suggest that the large-scale morphology of a galaxy is regulated by its mass and dynamical state. We show that the significant scatter in the M* -j relation is accounted for by the fact that, at fixed stellar mass, the contribution of ordered motions to the dynamical support of galaxies varies by at least a factor of 3. Indeed, the stellar spin parameter (quantified via λR ) correlates strongly with Sérsic and concentration indices. This correlation is particularly strong once slow rotators are removed from the sample, showing that late-type galaxies and early-type fast rotators form a continuous class of objects in terms of their kinematic properties. [ABSTRACT FROM AUTHOR]- Published
- 2016
- Full Text
- View/download PDF
38. GAMA/H-ATLAS: a meta-analysis of SFR indicators - comprehensive measures of the SFR-M* relation and cosmic star formation history at z < 0.4.
- Author
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Davies, L. J. M., Driver, S. P., Robotham, A. S. G., Grootes, M. W., Popescu, C. C., Tuffs, R. J., Hopkins, A., Alpaslan, M., Andrews, S. K., Bland-Hawthorn, J., Bremer, M. N., Brough, S., Brown, M. J. I., Cluver, M. E., Croom, S., da Cunha, E., Dunne, L., Lara-López, M. A., Liske, J., and Loveday, J.
- Subjects
STAR formation ,META-analysis ,COSMIC rays ,SPIRAL galaxies ,STELLAR luminosity function - Abstract
We present a meta-analysis of star formation rate (SFR) indicators in the Galaxy And Mass Assembly (GAMA) survey, producing 12 different SFR metrics and determining the SFR- M* relation for each. We compare and contrast published methods to extract the SFR from each indicator, using a well-defined local sample of morphologically selected spiral galaxies, which excludes sources which potentially have large recent changes to their SFR. The different methods are found to yield SFR-M* relations with inconsistent slopes and normalizations, suggesting differences between calibration methods. The recovered SFR-M* relations also have a large range in scatter which, as SFRs of the targets may be considered constant over the different time-scales, suggests differences in the accuracy by which methods correct for attenuation in individual targets. We then recalibrate all SFR indicators to provide new, robust and consistent luminosity-to-SFR calibrations, finding that the most consistent slopes and normalizations of the SFR-M* relations are obtained when recalibrated using the radiation transfer method of Popescu et al. These new calibrations can be used to directly compare SFRs across different observations, epochs and galaxy populations. We then apply our calibrations to the GAMA II equatorial data set and explore the evolution of star formation in the local Universe. We determine the evolution of the normalization to the SFR-M* relation from 0 < z < 0.35 - finding consistent trends with previous estimates at 0.3 < z < 1.2. We then provide the definitive z < 0.35 cosmic star formation history, SFR-M* relation and its evolution over the last 3 billion years. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
39. Galaxy And Mass Assembly: accurate panchromatic photometry from optical priors using LAMBDAR.
- Author
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Wright, A. H., Robotham, A. S. G., Bourne, N., Driver, S. P., Dunne, L., Maddox, S. J., Alpaslan, M., Andrews, S. K., Bauer, A. E., Bland-Hawthorn, J., Brough, S., Brown, M. J. I., Clarke, C., Cluver, M., Davies, L. J. M., Grootes, M. W., Holwerda, B. W., Hopkins, A. M., Jarrett, T. H., and Kafle, P. R.
- Subjects
ASTRONOMICAL photometry ,MULTIFREQUENCY antennas ,OPTICAL imaging sensors ,ASTRONOMY - Abstract
We present the Lambda Adaptive Multi-Band Deblending Algorithm in R (LAMBDAR), a novel code for calculating matched aperture photometry across images that are neither pixel- nor PSF-matched, using prior aperture definitions derived from high-resolution optical imaging. The development of this program is motivated by the desire for consistent photometry and uncertainties across large ranges of photometric imaging, for use in calculating spectral energy distributions. We describe the program, specifically key features required for robust determination of panchromatic photometry: propagation of apertures to images with arbitrary resolution, local background estimation, aperture normalization, uncertainty determination and propagation, and object deblending. Using simulated images, we demonstrate that the program is able to recover accurate photometric measurements in both high-resolution, low-confusion, and low-resolution, high-confusion, regimes. We apply the program to the 21-band photometric data set from the Galaxy And Mass Assembly (GAMA) Panchromatic Data Release (PDR; Driver et al. 2016), which contains imaging spanning the far-UV to the far-IR. We compare photometry derived from LAMBDAR with that presented in Driver et al. (2016), finding broad agreement between the data sets. None the less, we demonstrate that the photometry from LAMBDAR is superior to that from the GAMA PDR, as determined by a reduction in the outlier rate and intrinsic scatter of colours in the LAMBDAR data set. We similarly find a decrease in the outlier rate of stellar masses and star formation rates using LAMBDAR photometry. Finally, we note an exceptional increase in the number of UV and mid-IR sources able to be constrained, which is accompanied by a significant increase in the mid-IR colour-colour parameter-space able to be explored. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
40. Galaxy And Mass Assembly (GAMA): Improved emission lines measurements in four representative samples at 0.07 < z < 0.3.
- Author
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Rodrigues, M., Foster, C., Taylor, E. N., Wright, A. H., Hopkins, A. M., Baldry, I., Brough, S., Bland-Hawthorn, J., Cluver, M. E., Lara-López, M. A., Liske, J., López-Sánchez, Á. R., and Pimbblet, K. A.
- Subjects
GALAXIES ,STELLAR mass ,DENSITY of stars ,STELLAR evolution ,ASTRONOMICAL photometry - Abstract
This paper presents a new catalog of emission lines based on the GAMA II data for galaxies between 0:07 < z < 0:34. The catalog includes four subsamples containing 3000 galaxies drawn from the GAMA II survey and spanning four redshift windows. The four samples are representative of intermediate-mass galaxies down to log M
* > 9.4 at z ∼ 0:1 and log M* > 10.6 at z ∼ 0:30. We have developed a dedicated code called MARVIN that automates the main steps of the data analysis, but imposes visual individual quality control of each measurement. We use this catalog to investigate how the sample selection influences the shape of the stellar mass - metallicity relation. We find that commonly used selection criteria on line detections and by AGN rejection could affect the shape and dispersion of the high-mass end of the M - Z relation. For log M* > 10.6, common selection criteria reject about 65% of the emission-line galaxies. We also find that the relation does not evolve significantly from z = 0:07 to z = 0:34 in the range of stellar mass for which the samples are representative (log M* > 10.6). For lower stellar masses (log M* < 10.2) we are able to show that the observed 0.15 dex metallicity decrease in the same redshift range is a consequence of a color bias arising from selecting targets in the r-band. We highlight that this color selection bias affects all samples selected in r-band (e.g., GAMA and SDSS), even those drawn from volume-limited samples. Previously reported evolution of the M - Z relation at various redshifts may need to be revised to evaluate the effect of this selection bias. [ABSTRACT FROM AUTHOR]- Published
- 2016
- Full Text
- View/download PDF
41. Galaxy And Mass Assembly (GAMA): growing up in a bad neighbourhood - how do low-mass galaxies become passive?
- Author
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Davies, L. J. M., Robotham, A. S. G., Driver, S. P., Alpaslan, M., Baldry, I. K., Bland-Hawthorn, J., Brough, S., Brown, M. J. I., Cluver, M. E., Holwerda, B. W., Hopkins, A. M., Lara-López, M. A., Mahajan, S., Moffett, A. J., Owers, M. S., and Phillipps, S.
- Subjects
GALAXIES ,TIDAL stripping (Astrophysics) ,ASTRONOMY ,NOVAE (Astronomy) ,CONSTELLATIONS - Abstract
Both theoretical predictions and observations of the very nearby Universe suggest that lowmass galaxies(log10[M
* /M☉ ] < 9.5) are likely to remain star-forming unless they are affected by their local environment. To test this premise, we compare and contrast the local environment of both passive and star-forming galaxies as a function of stellar mass, using the Galaxy and Mass Assembly survey. We find that passive fractions are higher in both interacting pair and group galaxies than the field at all stellar masses, and that this effect is most apparent in the lowest mass galaxies. We alsofind that essentially all passive log10[M* /M☉ ] < 8.5 galaxies are found in pair/group environments, suggesting that local interactions with a more massive neighbour cause them to cease forming new stars. We find that the effects of immediate environment (local galaxy-galaxy interactions) in forming passive systems increase with decreasing stellar mass, and highlight that this is potentially due to increasing interaction time-scales giving sufficient time for the galaxy to become passive via starvation. We then present a simplistic model to test this premise, and showthat given our speculative assumptions, it is consistent with our observed results. [ABSTRACT FROM AUTHOR]- Published
- 2016
- Full Text
- View/download PDF
42. The SAMI Galaxy Survey: can we trust aperture corrections to predict star formation?
- Author
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Richards, S. N., Bryant, J. J., Croom, S. M., Hopkins, A. M., Schaefer, A. L., Bland-Hawthorn, J., Allen, J. T., Brough, S., Cecil, G., Cortese, L., Fogarty, L. M. R., Gunawardhana, M. L. P., Goodwin, M., Green, A. W., Ho, I. -T., Kewley, L. J., Konstantopoulos, I. S., Lawrence, J. S., Lorente, N. P. F., and Medling, A. M.
- Subjects
REDSHIFT ,GALAXIES ,SPECTRUM analysis ,ASTRONOMY ,ASTROPHYSICS - Abstract
In the low-redshift Universe (z < 0.3), our view of galaxy evolution is primarily based on fibre optic spectroscopy surveys. Elaborate methods have been developed to address aperture effects when fixed aperture sizes only probe the inner regions for galaxies of ever decreasing redshift or increasing physical size. These aperture corrections rely on assumptions about the physical properties of galaxies. The adequacy of these aperture corrections can be tested with integralfield spectroscopic data. We use integral-field spectra drawn from 1212 galaxies observed as part of the SAMI Galaxy Survey to investigate the validity of two aperture correction methods that attempt to estimate a galaxy's total instantaneous star formation rate.We show that biases arise when assuming that instantaneous star formation is traced by broad-band imaging, and when the aperture correction is built only from spectra of the nuclear region of galaxies. These biases may be significant depending on the selection criteria of a survey sample. Understanding the sensitivities of these aperture corrections is essential for correct handling of systematic errors in galaxy evolution studies. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
43. Galaxy And Mass Assembly (GAMA): the bright void galaxy population in the optical and mid-IR.
- Author
-
Penny, S. J., Brown, M. J. I., Pimbblet, K. A., Cluver, M. E., Croton, D. J., Owers, M. S., Lange, R., Alpaslan, M., Baldry, I., Bland-Hawthorn, J., Brough, S., Driver, S. P., Holwerda, B. W., Hopkins, A. M., Jarrett, T. H., Jones, D. Heath, Kelvin, L. S., Lara-López, M. A., Liske, J., and López-Sánchez, A. R.
- Subjects
GALAXIES ,STELLAR populations ,INFRARED radiation ,STAR formation ,ASTRONOMICAL photometry ,GALACTIC evolution - Abstract
We examine the properties of galaxies in the Galaxies and Mass Assembly (GAMA) survey located in voids with radii >10 h
−1 Mpc. Utilizing the GAMA equatorial survey, 592 void galaxies are identified out to z ≈ 0.1 brighter than Mr = −18.4, our magnitude completeness limit. Using the WHα versus [Nii]/Hα (WHAN) line strength diagnostic diagram, we classify their spectra as star forming, AGN, or dominated by old stellar populations. For objects more massive than 5 × 109 M⊙ , we identify a sample of 26 void galaxies with old stellar populations classed as passive and retired galaxies in the WHAN diagnostic diagram, else they lack any emission lines in their spectra. When matched to Wide-field Infrared Survey Explorer mid-IR photometry, these passive and retired galaxies exhibit a range of mid-IR colour, with a number of void galaxies exhibiting [4.6] − [12] colours inconsistent with completely quenched stellar populations, with a similar spread in colour seen for a randomly drawn non-void comparison sample. We hypothesize that a number of these galaxies host obscured star formation, else they are star forming outside of their central regions targeted for single-fibre spectroscopy. When matched to a randomly drawn sample of non-void galaxies, the void and non-void galaxies exhibit similar properties in terms of optical and mid-IR colour, morphology, and star formation activity, suggesting comparable mass assembly and quenching histories. A trend in mid-IR [4.6] − [12] colour is seen, such that both void and non-void galaxies with quenched/passive colours <1.5 typically have masses higher than 1010 M⊙ , where internally driven processes play an increasingly important role in galaxy evolution. [ABSTRACT FROM AUTHOR]- Published
- 2015
- Full Text
- View/download PDF
44. Galaxy And Mass Assembly (GAMA): the effect of close interactions on star formation in galaxies.
- Author
-
Davies, L. J. M., Robotham, A. S. G., Driver, S. P., Alpaslan, M., Baldry, I. K., Bland-Hawthorn, J., Brough, S., Brown, M. J. I., Cluver, M. E., Drinkwater, M. J., Foster, C., Grootes, M. W., Konstantopoulos, I. S., Lara-López, M. A., López-Sánchez, Á. R., Loveday, J., Meyer, M. J., Moffett, A. J., Norberg, P., and Owers, M. S.
- Subjects
STELLAR evolution ,ASTRONOMICAL observations ,COMPARATIVE studies ,ASTROPHYSICS ,METAPHYSICAL cosmology - Abstract
The modification of star formation (SF) in galaxy interactions is a complex process, with SF observed to be both enhanced in major mergers and suppressed in minor pair interactions. Such changes likely to arise on short time-scales and be directly related to the galaxy-galaxy interaction time. Here we investigate the link between dynamical phase and direct measures of SF on different time-scales for pair galaxies, targeting numerous star- formation rate (SFR) indicators and comparing to pair separation, individual galaxy mass and pair mass ratio. We split our sample into the higher (primary) and lower (secondary) mass galaxies in each pair and find that SF is indeed enhanced in all primary galaxies but suppressed in secondaries of minor mergers. We find that changes in SF of primaries are consistent in both major and minor mergers, suggesting that SF in the more massive galaxy is agnostic to pair mass ratio. We also find that SF is enhanced/suppressed more strongly for short-duration SFR indicators (e.g. Ha), highlighting recent changes to SF in these galaxies, which are likely to be induced by the interaction. We propose a scenario where the lower mass galaxy has its SF suppressed by gas heating or stripping, while the higher mass galaxy has its SF enhanced, potentially by tidal gas turbulence and shocks. This is consistent with the seemingly contradictory observations for both SF suppression and enhancement in close pairs. [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
- View/download PDF
45. Galaxy And Mass Assembly (GAMA): bivariate functions of Ha star-forming galaxies.
- Author
-
Gunawardhana, M. L. P., Hopkins, A. M., Taylor, E. N., Bland-Hawthorn, J., Norberg, P., Baldry, I. K., Loveday, J., Owers, M. S., Wilkins, S. M., Colless, M., Brown, M. J. I., Driver, S. P., Alpaslan, M., Brough, S., Cluver, M., Croom, S., Kelvin, L., Lara-López, M. A., Liske, J., and López-Sánchez, A. R.
- Subjects
BIVARIATE analysis ,STELLAR evolution ,GALACTIC evolution ,LUMINOSITY ,STELLAR mass - Abstract
We present bivariate luminosity and stellar mass functions of
Hα star-forming galaxies drawn from the Galaxy And Mass Assembly (GAMA) survey. While optically deep spectroscopic observations of GAMA over a wide sky area enable the detection of a large number of 0.001 < SFRHα (M⊙ yr-1 ) < 100 galaxies, the requirement for anHα detection in targets selected from an r-band magnitude-limited survey leads to an incompleteness due to missing optically faint star-forming galaxies. Using z < 0.1 bivariate distributions as a reference we model the higher-z distributions, thereby approximating a correction for the missing optically faint star-forming galaxies to the local star formation rate (SFR) and M densities. Furthermore, we obtain the r-band luminosity functions (LFs) and stellar mass functions ofHα star-forming galaxies from the bivariate LFs. As our sample is selected on the basis of detectedHα emission, a direct tracer of ongoing star formation, this sample represents a true star-forming galaxy sample, and is drawn from both photometrically classified blue and red subpopulations, though mostly from the blue population. On average 20-30 per cent of red galaxies at all stellar masses are star forming, implying that these galaxies may be dusty star-forming systems. [ABSTRACT FROM AUTHOR]- Published
- 2015
- Full Text
- View/download PDF
46. Galaxy And Mass Assembly (GAMA): the unimodal nature of the dwarf galaxy population.
- Author
-
Mahajan, Smriti, Drinkwater, Michael J., Driver, S., Kelvin, Lee S., Hopkins, A. M., Baldry, I., Phillipps, S., Bland-Hawthorn, J., Brough, S., Loveday, J., Penny, Samantha J., and Robotham, A. S. G.
- Subjects
STAR formation ,DWARF galaxies ,ASTRONOMICAL photometry ,STELLAR populations ,STELLAR mass ,GALACTIC evolution - Abstract
In this paper we aim to (i) test the number of statistically distinct classes required to classify the local galaxy population and (ii) identify the differences in the physical and star formation properties of visually distinct galaxies. To accomplish this, we analyse the structural parameters - effective radius (R
eff ), effective surface brightness within Reff (<μ>e ), central surface brightness (μ0) and Sérsic index (n) - obtained by fitting the light profile of 432 galaxies (0.002 < z = 0.02; Viking Z band), and their spectral energy distribution using multiband photometry in 18 broad-bands to obtain the stellar mass (M*), the star formation rate (SFR), the specific SFR (sSFR) and the dust mass (Mdust ), respectively. We show that visually distinct, star-forming dwarf galaxies (irregulars, blue spheroids and low-surface-brightness galaxies) form a unimodal population in a parameter space mapped by <μ>e , μ0 , n, Reff , SFR, sSFR, M*, Mdust and (g - i). The SFR and sSFR distribution of passively evolving (dwarf) ellipticals on the other hand, statistically distinguish them from other galaxies with similar luminosity, while the giant galaxies clearly segregate into star-forming spirals and passive lenticulars. We therefore suggest that the morphology classification scheme(s) used in literature for dwarf galaxies only reflect the observational differences based on luminosity and surface brightness among the apparent distinct classes, rather than any physical differences between them. [ABSTRACT FROM AUTHOR]- Published
- 2015
- Full Text
- View/download PDF
47. The SAMI Galaxy Survey: Early Data Release.
- Author
-
Allen, J. T., Croom, S. M., Konstantopoulos, I. S., Bryant, J. J., Sharp, R., Cecil, G. N., Fogarty, L. M. R., Foster, C., Green, A. W., Ho, I.-T., Owers, M. S., Schaefer, A. L., Scott, N., Bauer, A. E., Baldry, I., Barnes, L. A., Bland-Hawthorn, J., Bloom, J. V., Brough, S., and Colless, M.
- Subjects
GALAXIES ,COMPRESSED sensing ,INTEGRAL field spectroscopy ,FIBER optical sensors ,ASTRONOMICAL observations ,ASTRONOMICAL observatories - Abstract
We present the Early Data Release of the Sydney-AAO Multi-object Integral field spectrograph (SAMI) Galaxy Survey. The SAMI Galaxy Survey is an ongoing integral field spectroscopic survey of 3400 low-redshift (z < 0.12) galaxies, covering galaxies in the field and in groups within the Galaxy And Mass Assembly (GAMA) survey regions, and a sample of galaxies in clusters. In the Early Data Release, we publicly release the fully calibrated data cubes for a representative selection of 107 galaxies drawn from the GAMA regions, along with information about these galaxies from the GAMA catalogues. All data cubes for the Early Data Release galaxies can be downloaded individually or as a set from the SAMI Galaxy Survey website. In this paper we also assess the quality of the pipeline used to reduce the SAMI data, giving metrics that quantify its performance at all stages in processing the raw data into calibrated data cubes. The pipeline gives excellent results throughout, with typical sky subtraction residuals in the continuum of 0.9-1.2 per cent, a relative flux calibration uncertainty of 4.1 per cent (systematic) plus 4.3 per cent (statistical), and atmospheric dispersion removed with an accuracy of 0.09 arcsec, less than a fifth of a spaxel. [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
- View/download PDF
48. Ionized gas kinematics of galaxies in the CALIFA survey.
- Author
-
García-Lorenzo, B., Márquez, I., Barrera-Ballesteros, J. K., Masegosa, J., Husemann, B., Falcón-Barroso, J., Lyubenova, M., Sánchez, S. F., Walcher, J., Mast, D., García-Benito, R., Méndez-Abreu, J., van de Ven, G., Spekkens, K., Holmes, L., Monreal-Ibero, A., del Olmo, A., Ziegler, B., Bland-Hawthorn, J., and Sánchez-Blázquez, P.
- Subjects
IONIZED gases ,KINEMATICS ,GALAXIES ,GALACTIC evolution ,STELLAR evolution ,RADIAL velocity of stars - Abstract
Context. Ionized gas kinematics provide important clues to the dynamical structure of galaxies and hold constraints to the processes driving their evolution. Aims. The motivation of this work is to provide an overall characterization of the kinematic behavior of the ionized gas of the galaxies included in the Calar Alto Legacy Integral field Area (CALIFA), offering kinematic clues to potential users of the CALIFA survey for including kinematical criteria in their selection of targets for specific studies. From the first 200 galaxies observed by CALIFA survey in its two configurations, we present the two-dimensional kinematic view of the 177 galaxies satisfaying a gas content/detection threshold. Methods. After removing the stellar contribution, we used the cross-correlation technique to obtain the radial velocity of the dominant gaseous component for each spectrum in the CALIFA data cubes for different emission lines (namely, [O ii] λλ3726, 3729, [OIII] λλ4959, 5007, Hα+[N II] λλ6548, 6584, and [SII]λλ6716, 6730). The main kinematic parameters measured on the plane of the sky were directly derived from the radial velocities with no assumptions on the internal prevailing motions. Evidence of the presence of several gaseous components with different kinematics were detected by using [OIII] λλ4959, 5007 emission line profiles. Results. At the velocity resolution of CALIFA, most objects in the sample show regular velocity fields, although the ionized-gas kinematics are rarely consistent with simple coplanar circular motions. Thirty-five percent of the objects present evidence of a displacement between the photometric and kinematic centers larger than the original spaxel radii. Only 17% of the objects in the sample exhibit kinematic lopsidedness when comparing receding and approaching sides of the velocity fields, but most of them are interacting galaxies exhibiting nuclear activity (AGN or LINER). Early-type (E+S0) galaxies in the sample present clear photometric-kinematic misaligments. There is evidence of asymmetries in the emission line profiles in 117 out of the 177 analyzed galaxies, suggesting the presence of kinematically distinct gaseous components located at different distances from the optical nucleus. The kinematic decoupling between the dominant and secondary component/s suggested by the observed asymmetries in the profiles can be characterized by a limited set of parameters. Conclusions. This work constitutes the first determination of the ionized gas kinematics of the galaxies observed in the CALIFA survey. The derived velocity fields, the reported kinematic distortions/peculiarities and the identification of the presence of several gaseous components in different regions of the objects might be used as additional criteria for selecting galaxies for specific studies. [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
- View/download PDF
49. Galaxy And Mass Assembly (GAMA): the dependence of the galaxy luminosity function on environment, redshift and colour.
- Author
-
McNaught-Roberts, Tamsyn, Norberg, Peder, Baugh, Carlton, Lacey, Cedric, Loveday, J., Peacock, J., Baldry, I., Bland-Hawthorn, J., Brough, S., Driver, Simon P., Robotham, A. S. G., and Vázquez-Mata, J. A.
- Subjects
GALACTIC redshift ,STELLAR luminosity function ,STAR formation ,GALAXY clusters ,BLACK holes - Abstract
We use 80 922 galaxies in the Galaxy And Mass Assembly (GAMA) survey to measure the galaxy luminosity function (LF) in different environments over the redshift range 0.04 < z < 0.26. The depth and size of GAMA allows us to define samples split by colour and redshift to measure the dependence of the LF on environment, redshift and colour. We find that the LF varies smoothly with overdensity, consistent with previous results, with little environmental dependent evolution over the last 3 Gyr. The modified GALFORM model predictions agree remarkably well with our LFs split by environment, particularly in the most overdense environments. The LFs predicted by the model for both blue and red galaxies are consistent with GAMA for the environments and luminosities at which such galaxies dominate. Discrepancies between the model and the data seen in the faint end of the LF suggest too many faint red galaxies are predicted, which is likely to be due to the over-quenching of satellite galaxies. The excess of bright blue galaxies predicted in underdense regions could be due to the implementation of AGN feedback not being sufficiently effective in the lower mass haloes. [ABSTRACT FROM AUTHOR]
- Published
- 2014
- Full Text
- View/download PDF
50. The SAMI Galaxy Survey: the discovery of a luminous, low-metallicity HII complex in the dwarf galaxy GAMA J141103.98-003242.3.
- Author
-
Richards, S. N., Schaefer, A. L., López-Sánchez, Á. R., Croom, S. M., Bryant, J. J., Sweet, S. M., Konstantopoulos, I. S., Allen, J. T., Bland-Hawthorn, J., Bloom, J. V., Brough, S., Fogarty, L. M. R., Goodwin, M., Green, A. W., Ho, I. -T., Kewley, L. J., Koribalski, B. S., Lawrence, J. S., Owers, M. S., and Sadler, E. M.
- Subjects
DWARF galaxies ,GALAXY formation ,INTEGRAL field spectroscopy ,STELLAR luminosity function ,STELLAR activity - Abstract
We present the discovery of a luminous unresolved H II complex on the edge of dwarf galaxy GAMA J141103.98-003242.3 using data from the Sydney-AAO Multi-object Integral field spectrograph (SAMI) Galaxy Survey. This dwarf galaxy is situated at a distance of ∼100 Mpc and contains an unresolved region of H II emission that contributes ∼70 per cent of the galaxy's Hα luminosity, located at the top end of established H II region luminosity functions. For the H II complex, we measure a star formation rate of 0.147 ± 0.041 M
⊙ yr-1 and a metal licity of 12+log(O/H) = 8.01 ± 0.05 that is lower than the rest of the galaxy by ∼0.2 dex. Data from the H I Parkes All-Sky Survey (HIPASS) indicate the likely presence of neutral hydrogen in the galaxy to potentially fuel ongoing and future star-forming events. We discuss various triggering mechanisms for the intense star formation activity of this H II complex, where the kinematics of the ionized gas are well described by a rotating disc and do not show any features indicative of interactions. We show that SAMI is an ideal instrument to identify similar systems to GAMA J141103.98-003242.3, and the SAMI Galaxy Survey is likely to find many more of these systems to aid in the understanding of their formation and evolution. [ABSTRACT FROM AUTHOR]- Published
- 2014
- Full Text
- View/download PDF
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