bluuebunny/crossref_metadata_2025_split huggingface dataset:
The evolving structure of massive quiescent galaxies
Authors: Damjanov Ivana ,   the GDDS team
Published: July 2013

AbstractThe evolution of size and shape of massive quiescent galaxies over cosmic history has been challenging to explain within standard models of galaxy assembly. Several mechanisms have been proposed to explain the size growth of these systems, including major mergers, expansion, and late accretion via a series of minor mergers. The central mass density is shown to be an excellent tool for discriminating between different evolutionary scenarios. We present here the analysis performed on a spectroscopic sample of ~500 quiescent systems with stellar masses M*>1010 M⊙ spanning the redshift range 0.2<z<2.7 for which we calculate stellar mass densities within central 1 kpc and show that this quantity evolves linearly with redshift. Our results do not change when only systems at constant number density are considered in order to account for the mass growth during mergers and to relate progenitors to their descendants. Discrepancy between our findings and other recent studies performed on an order of magnitude smaller samples emphasizes the need for larger homogeneous spectroscopic samples to be used in such analysis.
Evolution of the distribution of stellar mass and light since redshift of unity
Authors: Li Cheng 
Published: July 2013

AbstractWe use data from the Sloan Digital Sky Survey (SDSS) and the DEEP2 survey to characterize the distribution of stellar mass and light of galaxies in the low-redshift and z = 1 Universe. We investigate the clustering bias of stellar mass and light by comparing these to projected autocorrelations of dark matter estimated from the Millennium Simulations (MS). All of the autocorrelation and bias functions show systematic trends with spatial scale and waveband, which are impressively similar at the two redshifts. This shows that the well-established environmental dependence of stellar populations in the local Universe is already in place at z = 1. The recent MS-based galaxy formation simulation of Guo et al. (2011) reproduces the scale-dependent clustering of luminosity to an accuracy better than 30% in all bands and at both redshifts, but substantially overpredicts mass autocorrelations at separations below ~ 2 Mpc. Further comparison of the shapes of our stellar mass bias functions with those predicted by the model suggests that both the SDSS and DEEP2 data prefer a fluctuation amplitude of σ8 ~ 0.8 rather than the σ8 = 0.9 assumed by the MS.
Galaxy formation and evolution with the Dark Energy Survey
Authors: Capozzi Diego , Thomas Daniel , Maraston Claudia , Davies Luke J. M. 
Published: July 2013

AbstractThe Dark Energy Survey (DES) will be the new state-of the-art in large-scale galaxy imaging surveys. With 5,000 deg2, it will cover an area of the sky similar to SDSS-II, but will go over two magnitudes deeper, reaching 24th magnitude in all four optical bands (griz). DES will further provide observations in the redder Y-band and will be complemented with VISTA observations in the near-infrared bands JHK. Hence DES will furnish an unprecedented combination of sky and wavelength coverage and depth, unreached by any of the existing galaxy surveys. The very nature of the DES data set – large volume at intermediate photometric depth – allows us to probe galaxy formation and evolution within a cosmic-time range of ~ 10 Gyr and in different environments. In fact there will be many galaxy clusters available for galaxy evolution studies, given that one of the main aims of DES is to use their abundance to constrain the equation of state of dark energy. The X-ray follow up of these clusters, coupled with the use of gravitational lensing, will provide very precise measures of their masses, enabling us to study in detail the influence of the environment on galaxy formation and evolution processes. DES will leverage the study of these processes by allowing us to perform a detailed investigation of the galaxy luminosity and stellar mass functions and of the relationship between dark and baryonic matter as described by the Halo Occupation Distribution.
The GAMA Panchromatic Survey
Authors: Driver Simon P. 
Published: July 2013

AbstractThe Galaxy And Mass Assembly Survey (GAMA) has now been operating for almost 5 years gathering spectroscopic redshifts for five regions of sky spanning 300 sq degrees in total to a depth of r < 19.8 mag. The survey has amassed over 225,000 redshifts making it the third largest redshift campaign after the SDSS and BOSS surveys. The survey has two novel features that set it apart: (1) complete and uniform sampling to a fixed flux limit (r < 19.8 mag) regardless of galaxy clustering due to multiple-visits to each sky region, enabling the construction of high-fidelity catalogues of groups and pairs, (2) co-ordination with diverse imaging campaigns which together sample an extremely broad range along the electro-magnetic spectrum from the UV (GALEX) through optical (VST KIDs), near-IR (VISTA VIKING), mid-IR (WISE), far-IR (Herschel-Atlas), 1m (GMRT), and eventually 20cm continuum and rest-frame 21cm line measurements (ASKAP DINGO). Apart from the ASKAP campaign all multi-wavelength programmes are either complete or in the final stages of observations and the UV-far-IR data are expected to be fully merged by the end of 2013. This article provides a brief flavour of the coming panchromatic database which will eventually include measurements or upper-limits across 27 wavebands for 380,000 galaxies. GAMA DR2 is scheduled for the end of January 2013.
GAMA: The effect of environment on galaxy emission line properties
Authors: Steele Oliver , Thomas Daniel , Maraston Claudia , Etherington James ,   the GAMA collaboration
Published: July 2013

AbstractWe study the influence of environment on emission line properties using the Galaxy And Mass Assembly (GAMA) survey, taking care to disentangle the role of mass and environment. We look at the role of local density separating galaxies into classifications star forming, AGN, and SF/AGN composite using the BPT diagnostic diagram. We find that environment is generally less important as a driving factor than galaxy mass. The presence of emission lines, whether driven by star formation or central supermassive black hole activity mostly depends on galaxy mass consistently for all galaxy types.
Merger rates for early-type galaxies: combining clustering and luminosity function measurements
Authors: Padilla Nelson D. , Gawiser Eric , Christlein Daniel , Marchesini Danilo 
Published: July 2013

AbstractWe present a study of the evolution of early-type galaxies (ETGs) that combines luminosity function and clustering measurements. This technique shows that ETGs at a given redshift evolve into brighter galaxies in the rest-frame passively evolved optical at lower redshifts. Notice that this indicates that a stellar-mass selection at different redshifts does not necessarily provide samples of galaxies in a progenitor-descendant relationship. The comparison between high redshift ETGs and their likely descendants at z = 0 points to a higher number density for the progenitors by a factor 3 to 11, implying the need for mergers to decrease their number density by today. Because the progenitor-to-descendant ratios of luminosity density are consistent with the unit value, our results show no need for strong star-formation episodes in ETGs since z = 1, which indicates that the needed mergers are dry, i.e. gas free.
Is there evolution in the black hole - bulge relation?
Authors: Schulze Andreas , Wisotzki Lutz 
Published: July 2013

AbstractWe present a framework to investigate sample selection effects on the observed BH - bulge relation and its evolution with redshift. We particularly discuss an active fraction bias and a luminosity bias. Applying our framework to literature studies, we cannot find statistically significant evidence for an evolving BH-bulge relation.
Dark matter in massive galaxies
Authors: Gerhard Ortwin 
Published: July 2013

AbstractThe spatial distributions of luminous and dark matter in massive early-type galaxies (ETGs) reflect the formation processes which shaped these systems. This article reviews the predictions of cosmological simulations for the dark and baryonic components of ETGs, and the observational constraints from lensing, hydrostatic X-ray gas atmospheres, and outer halo stellar dynamics.
Massive bulges are not just ellipticals surrounded by disks
Authors: Gadotti Dimitri A. 
Published: July 2013

AbstractUsing results from parametric multi-component multi-band image fitting of 1000 local massive galaxies in the SDSS, I investigate scaling relations of elliptical galaxies and bulges of disk galaxies. I show that ellipticals and bulges occupy different loci in both the edge-on and face-on views of the fundamental plane. In addition, ellipticals and bulges have offset mass-size relations (see Fig. 1). These results imply that massive bulges are not just massive ellipticals with a surrounding disk, a misconception driven by early studies. This is evidence that massive ellipticals and bulges have different formation histories, with important consequences for studies on galaxy formation and evolution. Full details can be seen in Gadotti (2009).
2D kinematics of the edge-on spiral galaxy ESO 379-006
Authors: Rosado M. , Gabbasov R. F. , Repetto P. , Fuentes-Carrera I. , Amram P. , Martos M. , Hernandez O. 
Published: July 2013

AbstractWe present a kinematical study of the marginally edge-on galaxy ESO 379-006. With Fabry-Perot spectroscopy at Hα we obtain velocity maps, the radial velocity field, and position-velocity diagrams parallel to the major and to the minor axis of the galaxy. We build the rotation curve of the galaxy and discuss the role of projection effects. The twisting of isovelocities in the radial velocity field of the disk of ESO 379-006 as well as a kinematical asymmetry found in the position-velocity diagrams parallel to the minor axis suggest the existence of non-circular motions that can be modeled by including a radial inflow besides the rotation motion. Extraplanar Diffuse Ionized gas was detected in this galaxy both from the images and from its kinematics. It is possible that the diffuse gas is lagging in rotation.
On the general structure of giant low surface brightness galaxy Malin 2
Authors: Saburova A. S. , Kasparova A. V. , Katkov I. Yu. , Bizyaev D. V. , Chilingarian I. V. 
Published: July 2013

AbstractWe carried out the multicolor surface photometry in BVR and griz filters parallel with stellar kinematic measurements from the long slit spectra for the low surface brightness galaxy Malin 2. The use of the multicolor surface photometry as well as the available HI rotation curve allowed us to construct the mass distribution model of the galaxy. Photometrical and dynamical mass estimates agree with the dark halo mass fraction of about 70% within four disc radial scalelengths (~ 70 kpc). We used our dynamical model to obtain radial profiles of the equilibrium disc volume density and gas pressure in the galaxy midplane based on the available HI and CO data. The observed molecular gas fraction appears to be much higher than in the high surface brightness galaxies for a similar gas pressure.
The intriguing properties of local compact massive galaxies: What are they?
Authors: Ferré-Mateu A. , Vazdekis A. , Trujillo I. , Sánchez-Blázquez P. , Ricciardelli E. , de la Rosa I. G. 
Published: July 2013

AbstractStudying the properties of the few compact massive galaxies that exist in the local Universe (Trujillo et al. 2009) might provide a closer look to the nature of their high redshift (z ≥ 1.0) massive counterparts. By this means we have characterized their main kinematics, structural properties, stellar populations and star formation histories with a set of new high quality spectroscopic and imaging data (Ferré-Mateu et al. 2012 and Trujillo et al. 2012). These galaxies seem to be truly unique, as they do not follow the characteristic kinematics, stellar surface mass density profiles and stellar population patterns of present-day massive ellipticals or spirals of similar mass. They are, instead, more alike their high-z analogs.Summarizing, local compact massive galaxies are rare, unique and the perfect laboratory to study their high redshift counterparts.
Stellar Population Models
Authors: Maraston Claudia 
Published: July 2013

AbstractModelling stellar populations in galaxies is a key approach to gain knowledge on the still elusive process of galaxy formation as a function of cosmic time. In this review, after a summary of the state-of-art, I discuss three aspects of the modelling, that are particularly relevant to massive galaxies, the focus of this symposium, at low and high-redshift. These are the treatment of the Thermally-Pulsating Asymptotic Giant Branch phase, evidences of an unusual Initial Mass Function, and the effect of modern stellar libraries on the model spectral energy distribution.
Stellar population gradients in GASS
Authors: Johansson Jonas , Kauffmann Guinevere , Moran Sean 
Published: July 2013

AbstractWe study relationships between the stellar populations and interstellar medium in massive galaxies using the Galex Arecibo SDSS Survey (GASS). The sample consists of HI-observations (~1000 galaxies) and complementary H2-observations (330 galaxies) and long-slit spectroscopy (230 galaxies). Luminosity-weighted stellar population ages, metallicitites and element abundance ratios, are derived by fitting stellar population models of absorption line indices. We find that the ages correlate more strongly with molecular gas fraction (MH2/M*) than with neutral Hydrogen fraction (MHI/M*). This result strengthens the theory that H2 is a better tracer of star-formation than HI. The sample is dominated by negative metallicity-gradients and flat Mg/Fe-gradients. Galaxies with high MH2/M*-ratios show in general flat or weakly negative age-gradients. For low MH2/M*-ratios the age-gradients are overall negative. These results are in agreement with the inside-out galaxy formation scenario. For galaxies with high r90/r50-ratios, a sub-population show positive age-gradients indicating additional formation channels. Furthermore, for galaxies with high MH2/M*-ratios more massive systems have older stellar populations in their centers, suggesting downsizing within the inside-out formation scenario.
Probing the Build-Up of Stellar Mass in the Center of IR Luminous Major Mergers with HST
Authors: Haan Sebastian , Surace Jason , Armus Lee , Evans Aaron 
Published: July 2013

AbstractInteractions and mergers are important drivers of galaxy evolution, transform spiral galaxies into massive ellipticals, and fuel both powerful starbursts and massive nuclear black holes. In particular one galaxy population, namely Luminous Infrared Galaxies (LIRGs), are believed to be responsible for most of the star formation that happened in the history of the universe (see e.g. Le Floch et al. 2005, Caputi et al. 2007, Magnelli et al. 2009), and hence represent a critical phase in the evolution of galaxies where most of the galaxies mass is building up. During a merger process, violent relaxation acts on stars present in gas-rich progenitor disks, while the centers are structured by the relics of dissipational, compact starbursts, imprinting a central “extra light” component or “cusp” into the surface brightness profiles of merger remnants. Our HST NICMOS/WFC3 imaging program of the 88 most luminous LIRGs in the Great Observatories Allsky LIRG Survey (GOALS, see Armus et al. 2009) shows that the central luminosity surface density in nearby LIRGs increases significantly along the merger sequence, indicating that the gas inflow fuels a central starburst and subsequently builds a compact stellar cusp (Haan et al. 2011). A large fraction of all galaxies in our sample possess double or multiple nuclei (~63%). Half of these double nuclei are not visible in the HST B-band images due to dust obscuration, which implies strong limitations on the ability to detect the true nuclear structures of luminous infrared galaxies at high-redshift (z >2) and may explain some of the apparent discrepancy of the LIRG population and merger ratio between local and high-redshift galaxies. We find that ULIRGs (log[LIR/L⊙] > 12.0) have significantly smaller nuclear separations than LIRGs (log[LIR/L⊙] = 11.4 — 12.0) with a median value of 1.2 kpc and 6.7 kpc, respectively. In our sample, merger (regardless of whether LIRG or ULIRG) seem to be prevalent at two time scales (based on the projected nuclear separation and mass ratio of the nuclei): First, at a remaining merger time scale of 0.3<[t-tmerg]<1.3 Gyr (53% of mergers in our sample), and second, at [t-tmerg]~ 0 (26%), likely representing the first passage of interacting galaxies and the final nuclear coalescence, respectively, with a post-merger time (starburst phase after the nuclei merged) of roughly 300 Myrs.
On the Recovery of Galaxy Properties from Spectral Fits
Authors: Magris G. , Mateu C. , A. G. Bruzual , Cabrera I. 
Published: July 2013

AbstractWe show the results of a non-parametric, fully bayesian implementation of a spectral fitting algorithm, designed to calculate the main physical parameters that govern the galaxy assembly process. In this work, we present results from a statistical treatment of SED fitting that allows for easy recovery and visualization of the galaxy physical parameters.
Undressing M87 by Exposing its Most Private Globulars
Authors: Montes Mireia , Acosta-Pulido José A. , Prieto M. Almudena , Fernández-Ontiveros Juan A. 
Published: July 2013

AbstractWe present a multiwavelength photometric analysis of the innermost (3×3 kpc2) Globular Clusters (GCs) of M87. Their Spectral Energy Distributions (SEDs) were built with J and Ks imaging obtained with NaCo at the VLT, along with HST UV-optical archival data. Using both Galatic GC templates and stellar population models, we derived ages (> 10 Gyr) and metallicities ([Fe/H]~ −0.7) for these clusters (e.g: Cohen et al. 1998). These GCs have lower metallicities than its host galaxy. This agrees with the idea that the GC population formed earlier than the bulk of the stars.
Did brightest cluster galaxies experience more than one star formation epoch?
Authors: Viljoen D. N. , Loubser S. I. 
Published: July 2013

AbstractWe use the full spectrum fitting ability of ULySS, with the Pegase.HR stellar population model to fit the observed spectra of 40 brightest cluster galaxies in order to determine whether a single or a composite stellar population provided the most probable representation of the star formation history (SFH). We find that some galaxies in the sample have more complex SFHs.
The stellar initial mass function in the early universe revealed from old stellar populations in our neighbourhood
Authors: Komiya Yutaka , Yamada Shimako , Suda Takuma , Fujimoto Masayuki Y. 
Published: July 2013

AbstractWe present a new method to investigate the IMF in the early universe from observations of extremely metal-poor (EMP) stars. EMP stars are the low-mass survivors of stars which are formed in the early universe. We can give constraints on the IMF from statistics of the elemental abundances of the EMP stars in the Galactic halo.
Revealing the origin of the cold ISM in massive early-type galaxies
Authors: Davis T. A. , Alatalo K. , Bureau M. , Young L. , Blitz L. , Crocker A. , Bayet E. , Bois M. , Bournaud F. , Cappellari M. , Davies R. L. , Duc P-A. , de Zeeuw P. T. , Emsellem E. , Falcon-Barroso J. , Khochfar S. , Krajnovic D. , Kuntschner H. , Lablanche P.-Y. , McDermid R. M. , Morganti R. , Naab T. , Sarzi M. , Scott N. , Serra P. , Weijmans A. 
Published: July 2013

AbstractRecently, massive early-type galaxies have shed their red-and-dead moniker, thanks to the discovery that many host residual star formation. As part of the ATLAS-3D project, we have conducted a complete, volume-limited survey of the molecular gas in 260 local early-type galaxies with the IRAM-30m telescope and the CARMA interferometer, in an attempt to understand the fuel powering this star formation. We find that around 22% of early-type galaxies in the local volume host molecular gas reservoirs. This detection rate is independent of galaxy luminosity and environment. Here we focus on how kinematic misalignment measurements and gas-to-dust ratios can be used to put constraints on the origin of the cold ISM in these systems. The origin of the cold ISM seems to depend strongly on environment, with misaligned, dust poor gas (indicative of externally acquired material) being common in the field but completely absent in rich groups and in the Virgo cluster. Very massive galaxies also appear to be devoid of accreted gas. This suggests that in the field mergers and/or cold gas accretion dominate the gas supply, while in clusters internal secular processes become more important. This implies that environment has a strong impact on the cold gas properties of ETGs.
Dust Emission in Early-Type Galaxies with the Herschel Virgo Cluster Survey
Authors: di Serego Alighieri Sperello ,   members of the HeViCS team
Published: July 2013

AbstractWe have searched for dust in an optical sample of 910 Early-Type Galaxies (ETGs) in the Virgo cluster (447 of which are optically complete at mpg ≤ 18.0), extending also to the dwarf ETGs, using Herschel images at 100, 160, 250, 350 and 500 μm. Dust was found in 52 ETGs (46 are in the optically complete sample), including M87 and another 3 ETGs with strong synchrotron emisssion. Dust is detected in 17% of ellipticals, 41% of lenticulars, and in about 4% of dwarf ETGs. The dust-to-stars mass ratio increases with decreasing optical luminosity, and for some dwarf ETGs reaches values similar to those of the dusty late-type galaxies. Slowly rotating ETGs are more likely to contain dust than fast rotating ones. Only 8 ETGs have both dust and HI, while 39 have only dust and 8 have only HI, surprisingly showing that only rarely dust and HI survive together. ETGs with dust appear to be concentrated in the densest regions of the cluster, while those with HI tend to be at the periphery. ETGs with an X-ray active SMBH are more likely to have dust and vice versa the dusty ETGs are more likely to have an active SMBH.
The role of cold gas on the stellar mass - metallicity relation of nearby galaxies
Authors: Hughes Thomas M. 
Published: July 2013

AbstractWe investigate the relationship between stellar mass, metallicity and gas content for a magnitude- and volume-limited sample of 260 nearby late-type galaxies in different environments. Combining new oxygen abundance measurements with ultraviolet to near-infrared photometry and Hi 21 cm line observations, we observe the relationship between stellar mass and metallicity. We also find that, at fixed stellar mass, galaxies with lower gas fractions typically possess higher oxygen abundances. Gas-poor galaxies are typically more metal-rich. Our results indicate that internal evolutionary processes, rather than environmental effects, play a key role in shaping the stellar mass-metallicity relation.
Red Galaxies from Hot Halos in Cosmological Hydro Simulations
Authors: Gabor Jared 
Published: July 2013

AbstractI highlight three results from cosmological hydrodynamic simulations that yield a realistic red sequence of galaxies: 1) Major galaxy mergers are not responsible for shutting off star-formation and forming the red sequence. Starvation in hot halos is. 2) Massive galaxies grow substantially (~ × 2 in mass) after being quenched, primarily via minor (1:5) mergers. 3) Hot halo quenching naturally explains why galaxies are red when they either (a) are massive or (b) live in dense environments.