Stellar populations of galaxies in the ALHAMBRA survey up to z ∼ 1

Aims. We perform a comprehensive study of the stellar population properties (formation epoch, age, metallicity, and extinction) of quiescent galaxies as a function of size and stellar mass to constrain the physical mechanism governing the stellar mass assembly and the likely evolutive scenarios that explain their growth in size. Methods. After selecting all the quiescent galaxies from the ALHAMBRA survey by the dust-corrected stellar mass–colour diagram, we built a shared sample of ∼850 quiescent galaxies with reliable measurements of sizes from the HST. This sample is complete in stellar mass and luminosity, I ≤ 23. The stellar population properties were retrieved using the fitting code for spectral energy distributions called MUlti-Filter FITting for stellar population diagnostics (MUFFIT) with various sets of composite stellar population models. Age, formation epoch, metallicity, and extinction were studied on the stellar mass–size plane as function of size through a Monte Carlo approach. This accounted for uncertainties and degeneracy effects amongst stellar population properties. Results. The stellar population properties of quiescent galaxies and their stellar mass and size since z ∼ 1 are correlated. At fixed stellar mass, the more compact the quiescent galaxy, the older and richer in metals it is (1 Gyr and 0.1 dex, respectively). In addition, more compact galaxies may present slight lower extinctions than their more extended counterparts at the same stellar mass (< 0.1 mag). By means of studying constant regions of stellar population properties across the stellar mass–size plane, we obtained empirical relations to constrain the physical mechanism that governs the stellar mass assembly of the form M⋆ ∝ rcα, where α amounts to 0.50–0.55 ± 0.09. There are indications that support the idea that the velocity dispersion is tightly correlated with the stellar content of galaxies. The mechanisms driving the evolution of stellar populations can therefore be partly linked to the dynamical properties of galaxies, along with their gravitational potential.

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The stellar mass assembly of low-redshift, massive, central galaxies in SDSS and the TNG300 simulation

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/staa2306 ◽

2020 ◽

Vol 497 (4) ◽

pp. 4262-4275

Author(s):

Thomas M Jackson ◽

A Pasquali ◽

C Pacifici ◽

C Engler ◽

A Pillepich ◽

...

Keyword(s):

Spectral Energy Distribution ◽

Stellar Mass ◽

Spectral Energy ◽

Distribution Fitting ◽

Stellar Ages ◽

Mass Assembly ◽

Galaxy Assembly ◽

The Times ◽

Stellar Masses ◽

Kinetic Mode

ABSTRACT The stellar mass assembly of galaxies can be affected by both secular and environmental processes. In this study, for the first time, we investigate the stellar mass assembly of $\sim 90\, 000$ low-redshift, central galaxies selected from SDSS group catalogues ($M_{\rm Stellar}\gtrsim 10^{9.5}\, \mathrm{M}_{\odot }$, $M_{\rm Halo}\gtrsim 10^{12}\, \mathrm{M}_{\odot }$) as a function of both stellar mass and halo mass. We use estimates of the times at which 10, 50, and 90 per cent of the stellar mass were assembled from photometric spectral energy distribution fitting, allowing a more complete investigation than single stellar ages alone. We consider trends in both stellar mass and halo mass simultaneously, finding dependences of all assembly times on both. We find that galaxies with higher stellar masses (at constant halo mass) have on average older lookback times, similar to previous studies of galaxy assembly. We also find that galaxies at higher halo mass (at constant stellar mass) have younger lookback times, possibly due to a larger reservoir of gas for star formation. An exception to this is a subsample with high stellar-to-halo mass ratios, which are likely massive, field spirals. We compare these observed trends to those predicted by the TNG300 simulation, finding good agreement overall as a function of either stellar mass or halo mass. However, some differences in the assembly times (of up to ∼3 Gyr) appear when considering both stellar mass and halo mass simultaneously, noticeably at intermediate stellar masses (MStellar ∼ 1011 M⊙). These discrepancies are possibly linked to the quenched fraction of galaxies and the kinetic mode active galactic nucleus feedback implemented in TNG300.

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The Stellar Mass of M31 as inferred by the Andromeda Optical & Infrared Disk Survey

Proceedings of the International Astronomical Union ◽

10.1017/s1743921315003440 ◽

2014 ◽

Vol 10 (S311) ◽

pp. 82-85 ◽

Cited By ~ 6

Author(s):

Jonathan Sick ◽

Stephane Courteau ◽

Jean-Charles Cuillandre ◽

Julianne Dalcanton ◽

Roelof de Jong ◽

...

Keyword(s):

Stellar Population ◽

Spectral Energy Distribution ◽

Major Axis ◽

Stellar Mass ◽

Spectral Energy ◽

Population Synthesis ◽

Disk Formation ◽

Infrared Spectral ◽

Inside Out ◽

Additional Constraints

AbstractOur proximity and external vantage point make M31 an ideal testbed for understanding the structure of spiral galaxies. The Andromeda Optical and Infrared Disk Survey (ANDROIDS) has mapped M31's bulge and disk out to R=40 kpc in ugriJKs bands with CFHT using a careful sky calibration. We use Bayesian modelling of the optical-infrared spectral energy distribution (SED) to estimate profiles of M31's stellar populations and mass along the major axis. This analysis provides evidence for inside-out disk formation and a declining metallicity gradient. M31's i-band mass-to-light ratio (M/Li*) decreases from 0.5 dex in the bulge to ~ 0.2 dex at 40 kpc. The best-constrained stellar population models use the full ugriJKs SED but are also consistent with optical-only fits. Therefore, while NIR data can be successfully modelled with modern stellar population synthesis, NIR data do not provide additional constraints in this application. Fits to the gi-SED alone yield M/Li* that are systematically lower than the full SED fit by 0.1 dex. This is still smaller than the 0.3 dex scatter amongst different relations for M/Li via g – i colour found in the literature. We advocate a stellar mass of M*(30 kpc) = 10.3+2.3-1.7 × 1010 M⊙ for the M31 bulge and disk.

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Probing Stellar Mass Assembly in the Virgo Cluster

Proceedings of the International Astronomical Union ◽

10.1017/s1743921310003510 ◽

2009 ◽

Vol 5 (S262) ◽

pp. 420-421

Author(s):

Joel C. Roediger ◽

Stéphane Courteau ◽

Michael McDonald ◽

Lauren A. MacArthur

Keyword(s):

Representative Sample ◽

Recent Literature ◽

Stellar Mass ◽

Virgo Cluster ◽

Stellar Content ◽

Hubble Sequence ◽

Gas Removal ◽

Mass Assembly ◽

Stellar Properties

AbstractWe have examined in detail both the resolved and integrated stellar content of a representative sample of galaxies in the Virgo cluster to constrain plausible formation/evolution scenarios for them. Systematic variations in age and metallicity gradients along the Hubble sequence are found such that the gradients become more negative for later types. Combined with correlations of the above stellar properties with both structure and environment, these data highlight the significance of merging in the assembly of massive spheroids and environmental phenomena (gas removal/interactions) in the evolution of disks and dwarf systems. Our data also provide useful perspectives on a number of important topics in the recent literature.

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Stellar Population Models of Distant Radio Galaxies

Symposium - International Astronomical Union ◽

10.1017/s0074180900081948 ◽

1996 ◽

Vol 175 ◽

pp. 588-590

Author(s):

D. Villani ◽

S. Di Serego Alighieri

Keyword(s):

Energy Distribution ◽

Galaxy Formation ◽

Stellar Population ◽

Spectral Energy Distribution ◽

Formation Rate ◽

Stellar Populations ◽

Radio Galaxies ◽

Initial Mass Function ◽

Spectral Energy ◽

The Galaxy

Stellar populations of high redshift radio galaxies (HzRG) (z up to 4.2) are the oldest stellar systems known, that is the ones formed at the earliest cosmological epochs. Therefore they are the best objects for providing us with information about the epoch of galaxy formation. The information on the stellar populations in HzRG are obtained from the study of their Integrated Spectral Energy Distribution (ISED) which are gathered both from spectra and integrated magnitudes. The most common approach for the interpretation of colors and spectral features of the energy distribution of galaxies is the Evolutionary Population Synthesis (EPS), which has been introduced for the first time by Tinsley in 1972. EPS models have often been used in the past to interpret the ISED of HzRG (Chambers & Charlot 1990; Lilly & Longair 1984; di Serego Alighieri et al. 1994) in order to draw conclusions on the age of the stellar populations and therefore on the epoch of galaxy formation. The results are sometimes conflicting and a number of very recent EPS models have become available (Bressan et al. 1995; Bruzual & Charlot 1993; Buzzoni 1989; Guiderdoni & Rocca-Volmerange 1987): we are therefore analysing the differences between the various EPS models with the aim of assessing their suitability to study the stellar population at early epochs. The EPS models assume for stars a given Initial Mass Function(IMF) as well as a Star Formation Rate (SFR). Then one can compute the number of stars with given mass present in the galaxy as a function of time. The position of each star in the HR diagram is determined by means of the isochrones, which are calculated from stellar evolutionary models. The ISED of a galaxy is obtained from the superposition of the spectra of single stars obtained from a stellar spectral library. Thus these models describe the galaxy ISED as a function of the time, giving a complete evolutionary picture.

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Dynamical masses of brightest cluster galaxies – II. Constraints on the stellar IMF

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/staa3530 ◽

2020 ◽

Vol 500 (3) ◽

pp. 4153-4165

Author(s):

S I Loubser ◽

H Hoekstra ◽

A Babul ◽

Y M Bahé ◽

M Donahue

Keyword(s):

Gravitational Lensing ◽

Stellar Population ◽

Population Analysis ◽

Stellar Populations ◽

Stellar Mass ◽

Initial Mass Function ◽

Dynamical Mass ◽

Cluster Galaxies ◽

Brightest Cluster Galaxies ◽

Mass Profiles

ABSTRACT We use stellar and dynamical mass profiles, combined with a stellar population analysis, of 32 brightest cluster galaxies (BCGs) at redshifts of 0.05 ≤$z$ ≤ 0.30, to place constraints on their stellar initial mass function (IMF). We measure the spatially resolved stellar population properties of the BCGs, and use it to derive their stellar mass-to-light ratios ($\Upsilon _{\star \rm POP}$). We find young stellar populations (<200 Myr) in the centres of 22 per cent of the sample, and constant $\Upsilon _{\star \rm POP}$ within 15 kpc for 60 per cent of the sample. We further use the stellar mass-to-light ratio from the dynamical mass profiles of the BCGs ($\Upsilon _{\star \rm DYN}$), modelled using a multi-Gaussian expansion and Jeans Anisotropic Method, with the dark matter contribution explicitly constrained from weak gravitational lensing measurements. We directly compare the stellar mass-to-light ratios derived from the two independent methods, $\Upsilon _{\star \rm POP}$ (assuming some IMF) to $\Upsilon _{\star \rm DYN}$ for the subsample of BCGs with no young stellar populations and constant $\Upsilon _{\star \rm POP}$. We find that for the majority of these BCGs, a Salpeter (or even more bottom-heavy) IMF is needed to reconcile the stellar population and dynamical modelling results although for a small number of BCGs, a Kroupa (or even lighter) IMF is preferred. For those BCGs better fit with a Salpeter IMF, we find that the mass-excess factor against velocity dispersion falls on an extrapolation (towards higher masses) of known literature correlations. We conclude that there is substantial scatter in the IMF amongst the highest mass galaxies.

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Stellar populations of galaxies in the ALHAMBRA survey up to z ∼ 1

Astronomy and Astrophysics ◽

10.1051/0004-6361/201832788 ◽

2019 ◽

Vol 631 ◽

pp. A156 ◽

Cited By ~ 2

Author(s):

L. A. Díaz-García ◽

A. J. Cenarro ◽

C. López-Sanjuan ◽

I. Ferreras ◽

M. Cerviño ◽

...

Keyword(s):

Star Formation ◽

Rest Frame ◽

Stellar Population ◽

Spectral Energy Distribution ◽

Formation Rate ◽

Stellar Mass ◽

Spectral Energy ◽

Population Parameters ◽

Star Forming ◽

Set Constraints

Aims. Our aim is to determine the distribution of stellar population parameters (extinction, age, metallicity, and star formation rates) of quiescent galaxies within the rest-frame stellar mass–colour diagrams and UVJ colour–colour diagrams corrected for extinction up to z ∼ 1. These novel diagrams reduce the contamination in samples of quiescent galaxies owing to dust-reddened galaxies, and they provide useful constraints on stellar population parameters only using rest-frame colours and/or stellar mass. Methods. We set constraints on the stellar population parameters of quiescent galaxies combining the ALHAMBRA multi-filter photo-spectra with our fitting code for spectral energy distribution, MUlti-Filter FITting (MUFFIT), making use of composite stellar population models based on two independent sets of simple stellar population (SSP) models. The extinction obtained by MUFFIT allowed us to remove dusty star-forming (DSF) galaxies from the sample of red UVJ galaxies. The distributions of stellar population parameters across these rest-frame diagrams are revealed after the dust correction and are fitted by LOESS, a bi-dimensional and locally weighted regression method, to reduce uncertainty effects. Results. Quiescent galaxy samples defined via classical UVJ diagrams are typically contaminated by a ∼20% fraction of DSF galaxies. A significant part of the galaxies in the green valley are actually obscured star-forming galaxies (∼30–65%). Consequently, the transition of galaxies from the blue cloud to the red sequence, and hence the related mechanisms for quenching, seems to be much more efficient and faster than previously reported. The rest-frame stellar mass–colour and UVJ colour–colour diagrams are useful for constraining the age, metallicity, extinction, and star formation rate of quiescent galaxies by only their redshift, rest-frame colours, and/or stellar mass. Dust correction plays an important role in understanding how quiescent galaxies are distributed in these diagrams and is key to performing a pure selection of quiescent galaxies via intrinsic colours.

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Stellar populations of HII galaxies

Astronomy and Astrophysics ◽

10.1051/0004-6361/201732275 ◽

2018 ◽

Vol 615 ◽

pp. A55 ◽

Cited By ~ 5

Author(s):

Eduardo Telles ◽

Jorge Melnick

Keyword(s):

Star Formation ◽

Stellar Population ◽

Spectral Energy Distribution ◽

Age Determination ◽

Stellar Mass ◽

Star Formation History ◽

Spectral Energy ◽

Model Parameters ◽

Formation History ◽

Star Formation Histories

Aims. We present a UV to mid-IR spectral energy distribution (SED) study of a large sample of SDSS DR13 HII galaxies. These galaxies are selected as starbursts (EW(Hα) > 50Å) and for their high-excitation locus in the upper left region of the BPT diagram. Their photometry was derived from the cross-matched GALEX, SDSS, UKDISS, and WISE catalogs. Methods. We used CIGALE modeling and a SED fitting routine with the parametrization of a three-burst star formation history, and a comprehensive analysis of all other model parameters. We were able to estimate the contribution of the underlying old stellar population to the observed equivalent width of Hβ, and allow for more accurate burst age determination. Results. We found that the star formation histories of HII Galaxies can be reproduced remarkably well by three major eras of star formation. In addition, the SED fitting results indicate that in all cases the current burst produces a small percent of the total stellar mass, i.e., the bulk of stellar mass in HII galaxies has been produced by the past episodes of star formation, and also indicate that at a given age the Hβ luminosity depends only on the mass of young stars favoring a universal IMF for massive stars. Most importantly, the current star formation episodes are maximum starbursts that produce stars at the highest possible rate.

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Multi-Wavelength Study of a Proto-BCG at z = 1.7

Galaxies ◽

10.3390/galaxies9040115 ◽

2021 ◽

Vol 9 (4) ◽

pp. 115

Author(s):

Quirino D’Amato ◽

Isabella Prandoni ◽

Marisa Brienza ◽

Roberto Gilli ◽

Cristian Vignali ◽

...

Keyword(s):

Spectral Energy Distribution ◽

Formation Rate ◽

Surrounding Medium ◽

Stellar Mass ◽

Host Galaxy ◽

Spectral Energy ◽

Starburst Galaxy ◽

Infrared Band ◽

Field Orientation ◽

Mass Assembly

In this work we performed a spectral energy distribution (SED) analysis in the optical/infrared band of the host galaxy of a proto-brightest bluster galaxy (BCG, NVSS J103023 + 052426) in a proto-cluster at z = 1.7. We found that it features a vigorous star formation rate (SFR) of ∼570 M⊙/yr and a stellar mass of M*∼3.7×1011M⊙; the high corresponding specific SFR = 1.5±0.5Gyr−1 classifies this object as a starburst galaxy that will deplete its molecular gas reservoir in ∼3.5×108 yr. Thus, this system represents a rare example of a proto-BCG caught during the short phase of its major stellar mass assembly. Moreover, we investigated the nature of the host galaxy emission at 3.3 mm. We found that it originates from the cold dust in the interstellar medium, even though a minor non-thermal AGN contribution cannot be completely ruled out. Finally, we studied the polarized emission of the lobes at 1.4 GHz. We unveiled a patchy structure where the polarization fraction increases in the regions in which the total intensity shows a bending morphology; in addition, the magnetic field orientation follows the direction of the bendings. We interpret these features as possible indications of an interaction with the intracluster medium. This strengthens the hypothesis of positive AGN feedback, as inferred in previous studies of this object on the basis of X-ray/mm/radio analysis. In this scenario, the proto-BCG heats the surrounding medium and possibly enhances the SFR in nearby galaxies.

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UV upturn versus UV weak galaxies: differences and similarities of their stellar populations unveiled by a de-biased sample

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/staa3447 ◽

2020 ◽

Vol 500 (2) ◽

pp. 1870-1883

Author(s):

M L L Dantas ◽

P R T Coelho ◽

P Sánchez-Blázquez

Keyword(s):

Star Formation ◽

Stellar Population ◽

Spectral Energy Distribution ◽

Formation Rate ◽

Principal Component ◽

Stellar Populations ◽

Spectral Energy ◽

Two Samples ◽

Star Formation Histories ◽

Uv Upturn

ABSTRACT The ultraviolet (UV) upturn is characterized by an unexpected up-rise of the UV flux in quiescent galaxies between the Lyman limit and 2500 Å. By making use of colour–colour diagrams, one can subdivide UV bright red-sequence galaxies in two groups: UV weak and upturn. With these two groups, we propose a comparison between their stellar population properties with the goal of establishing differences and similarities between them. We make use of propensity score matching to mitigate potential biases between the two samples, by selecting similar objects in terms of redshift and stellar mass. Also, we take advantage of spectral energy distribution (SED) fitting results from magphys made available by the GAMA collaboration. The analyses are made by comparing the distributions from the SED fitting directly, as well as investigating the differences in correlations between their parameters, and finally by using principal component analysis. We explore important differences and similarities between UV weak and upturn galaxies in terms of several parameters, such as: metallicity, age, specific star formation rate, time of last burst of star-formation, to mention a few. Notable differences are those concerning (g − r) colour, metallicity, and time since last burst of star-formation: UV upturn are redder in the optical, more metallic, and their last burst of star-formation happened earlier in time. These differences suggest that UV upturn systems have shorter star-formation histories (i.e. have been evolving more passively) when compared to UV weak galaxies. Consequently, these last seem to have a higher diversity of stellar populations.

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Rapid build-up of the stellar content in the protocluster core SPT2349−56 at z = 4.3

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/stab3539 ◽

2021 ◽

Author(s):

Ryley Hill Scott Chapman ◽

Kedar A Phadke ◽

Manuel Aravena ◽

Melanie Archipley ◽

Matthew L N Ashby ◽

...

Keyword(s):

Rest Frame ◽

Imaging Finding ◽

Mass Function ◽

Stellar Mass ◽

Spectral Energy ◽

Formation Mechanisms ◽

Stellar Content ◽

Cluster Galaxy ◽

Star Forming ◽

Stellar Masses

Abstract The protocluster SPT2349−56 at z = 4.3 contains one of the most actively star-forming cores known, yet constraints on the total stellar mass of this system are highly uncertain. We have therefore carried out deep optical and infrared observations of this system, probing rest-frame ultraviolet to infrared wavelengths. Using the positions of the spectroscopically-confirmed protocluster members, we identify counterparts and perform detailed source deblending, allowing us to fit spectral energy distributions in order to estimate stellar masses. We show that the galaxies in SPT2349−56 have stellar masses proportional to their high star-formation rates, consistent with other protocluster galaxies and field submillimetre galaxies (SMGs) around redshift 4. The galaxies in SPT2349−56 have on average lower molecular gas-to-stellar mass fractions and depletion timescales than field SMGs, although with considerable scatter. We construct the stellar-mass function for SPT2349−56 and compare it to the stellar-mass function of z = 1 galaxy clusters, finding consistent shapes between the two. We measure rest-frame galaxy ultraviolet half-light radii from our HST-F160W imaging, finding that on average the galaxies in our sample are similar in size to typical star-forming galaxies at these redshifts. However, the brightest HST-detected galaxy in our sample, found near the luminosity-weighted centre of the protocluster core, remains unresolved at this wavelength. Hydrodynamical simulations predict that the core galaxies will quickly merge into a brightest cluster galaxy, thus our observations provide a direct view of the early formation mechanisms of this class of object.

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