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2181. Masses and photometry of 304 M31 old star clusters
ID:
ivo://CDS.VizieR/J/AJ/149/56
Title:
Masses and photometry of 304 M31 old star clusters
Short Name:
J/AJ/149/56
Date:
21 Oct 2021
Publisher:
CDS
Description:
This paper presents CCD multicolor photometry for 304 old star clusters in the nearby spiral galaxy M31, from which the photometry of 55 star clusters is first obtained. The observations were carried out as a part of the Beijing-Arizona-Taiwan-Connecticut Multicolor Sky Survey from 1995 February to 2008 March, using 15 intermediate-band filters covering 3000-10000{AA}. Detailed comparisons show that our photometry is in agreement with previous measurements. Based on the ages and metallicities from Caldwell et al. and the photometric measurements here, we estimated the clusters' masses by comparing their multicolor photometry with stellar population synthesis models. The results show that the sample clusters have masses between ~3x10^4^M_{sun}_ and ~10^7^M_{sun}_ with a peak of ~4x10^5^_M{sun}_. The masses here are in good agreement with those in previous studies. Combined with the masses of young star clusters of M31 from Wang et al., we find that the peak mass of the old clusters is 10 times that of young clusters.
2182. 2MASS galaxy group catalog
ID:
ivo://CDS.VizieR/J/AJ/149/171
Title:
2MASS galaxy group catalog
Short Name:
J/AJ/149/171
Date:
21 Oct 2021
Publisher:
CDS
Description:
A galaxy group catalog is built from the sample of the 2MASS Redshift Survey almost complete to K_s_=11.75 over 91% of the sky. Constraints in the construction of the groups were provided by scaling relations determined by close examination of well defined groups with masses between 10^11^ and 10^15^M_{sun}_. Group masses inferred from K_s_ luminosities are statistically in agreement with masses calculated from application of the virial theorem. While groups have been identified over the full redshift range of the sample, the properties of the nearest and farthest groups are uncertain and subsequent analysis has only considered groups with velocities between 3000 and 10000km/s. The 24044 galaxies in this range are identified with 13607 entities, 3461 of them with two or more members. A group mass function is constructed. The Sheth-Tormen formalism provides a good fit to the shape of the mass function for group masses above 6h^-1^x10^12^M_{sun}_ but the count normalization is poor. Summing all the mass associated with the galaxy groups between 3000 and 10000km/s gives a density of collapsed matter as a fraction of the critical density of {Omega}_collapsed_=0.16.
2183. Massive Compact Galaxies in MaNGA
ID:
ivo://CDS.VizieR/J/MNRAS/507/300
Title:
Massive Compact Galaxies in MaNGA
Short Name:
J/MNRAS/507/300
Date:
03 Dec 2021 00:51:01
Publisher:
CDS
Description:
We characterized the kinematics, morphology, and stellar population (SP) properties of a sample of massive compact quiescent galaxies (MCGs, 10<~logM*/M_{sun}_<~11 and re~1-3kpc) in the MaNGA Survey, with the goal of constraining their formation, assembly history, and assessing their relation with non-compact quiescent galaxies. We compared their properties with those of a control sample of median-sized quiescent galaxies (re~4-8kpc) with similar effective velocity dispersions. MCGs have elevated rotational support, as evidenced by a strong anticorrelation between the Gauss-Hermite moment h3 and V/{sigma}. In contrast, 30 per cent of control sample galaxies (CSGs) are slow rotators, and fast-rotating CSGs generally show a weak h3-V/{sigma} anticorrelation. MCGs and CSGs have similar ages, but MCGs are more metal-rich and {alpha}-enhanced. Both MCGs and CSGs have shallow negative metallicity gradients and flat [{alpha}/Fe] gradients. On average, MCGs and CSGs have flat age gradients, but CSGs have a significantly larger dispersion of gradient values. The kinematics and SP properties of MCGs suggest that they experienced highly dissipative gas-rich events, such as mergers, followed by an intense, short, and centrally concentrated burst of star formation, between 4 and 10Gyr ago (z~0.4-2), and had a quiet accretion history since then. This sequence of events might be analogous to, although less extreme than, the compaction events that formed compact quiescent galaxies at z~2. The small sizes of MCGs, and the high efficiency and short duration of their last star formation episode suggest that they are descendants of compact post-starburst galaxies.
2184. Massive discs in cosmological simulations
ID:
ivo://CDS.VizieR/J/A+A/640/A70
Title:
Massive discs in cosmological simulations
Short Name:
J/A+A/640/A70
Date:
21 Oct 2021
Publisher:
CDS
Description:
We investigate the disc-halo connection in massive (M*>5x10^10^M_{sun}_) disc galaxies from the cosmological hydrodynamical simulations EAGLE and IllustrisTNG, and compare it with that inferred from the study of HI rotation curves in nearby massive spirals from the Spitzer Photometry and Accurate Rotation Curves (SPARC) dataset. We find that discrepancies between the simulated and observed discs arise both on global and on local scales. Globally, the simulated discs inhabit halos that are a factor 4 (in EAGLE) and 2 (in IllustrisTNG) more massive than those derived from the rotation curve analysis of the observed dataset. We also use synthetic rotation curves of the simulated discs to demonstrate that the recovery of the halo masses from rotation curves are not systematically biased. We find that the simulations predict dark-matter dominated systems with stellar-to-total enclosed mass ratios that are a factor of 1.5-2 smaller than real galaxies at all radii. This is an alternative manifestation of the `failed feedback problem', since it indicates that simulated halos hosting massive discs have been too inefficient at converting their baryons into stars, possibly due to an overly efficient stellar and/or AGN feedback implementation.
2185. Massive early-type galaxies
ID:
ivo://CDS.VizieR/J/MNRAS/428/1460
Title:
Massive early-type galaxies
Short Name:
J/MNRAS/428/1460
Date:
21 Oct 2021
Publisher:
CDS
Description:
Present-day massive galaxies are composed mostly of early-type objects. It is unknown whether this was also the case at higher redshifts. In a hierarchical assembling scenario the morphological content of the massive population is expected to change with time from disc-like objects in the early Universe to spheroid-like galaxies at present. In this paper we have probed this theoretical expectation by compiling a large sample of massive (M_stellar_>=10^11^h^-2^_70_M{sun}) galaxies in the redshift interval 0<z<3. Our sample of 1082 objects comprises 207 local galaxies selected from Sloan Digital Sky Survey plus 875 objects observed with the Hubble Space Telescope belonging to the Palomar Observatory Wide-field InfraRed/DEEP2 and GOODS NICMOS Survey surveys. 639 of our objects have spectroscopic redshifts. Our morphological classification is performed as close as possible to the optical rest frame according to the photometric bands available in our observations both quantitatively (using the Sersic index as a morphological proxy) and qualitatively (by visual inspection). Using both techniques we find an enormous change on the dominant morphological class with cosmic time. The fraction of early-type galaxies among the massive galaxy population has changed from ~20-30 per cent at z~3 to~70 per cent at z=0. Early-type galaxies have been the predominant morphological class for massive galaxies since only z~1.
2186. Massive early-type galaxies in K-band
ID:
ivo://CDS.VizieR/J/ApJ/762/83
Title:
Massive early-type galaxies in K-band
Short Name:
J/ApJ/762/83
Date:
21 Oct 2021
Publisher:
CDS
Description:
We use high-resolution K-band VLT/HAWK-I imaging over 0.25deg^2^ to study the structural evolution of massive early-type galaxies since z~2. Mass-selected samples, complete down to log(M/M_{sun}_)~10.7 such that "typical" (L*) galaxies are included at all redshifts, are drawn from pre-existing photometric redshift surveys. We then separate the samples into different redshift slices and classify them as late- or early-type galaxies on the basis of their specific star formation rate. Axis-ratio measurements for the ~400 early-type galaxies in the redshift range 0.6<z<1.8 are accurate to 0.1 or better. The projected axis-ratio distributions are then compared with lower redshift samples. We find strong evidence for evolution of the population properties: early-type galaxies at z>1 are, on average, flatter than at z<1 and the median projected axis ratio at a fixed mass decreases with redshift. However, we also find that at all epochs z<~2, the most massive early-type galaxies (log(M/M_{sun}_)>11.3) are the roundest, with a pronounced lack of galaxies that are flat in projection. Merging is a plausible mechanism that can explain both results: at all epochs, merging is required for early-type galaxies to grow beyond log(M/M_{sun}_)~11.3, and all early types over time gradually and partially lose their disk-like characteristics.
2187. Massive galaxies environmental density
ID:
ivo://CDS.VizieR/J/MNRAS/471/2687
Title:
Massive galaxies environmental density
Short Name:
J/MNRAS/471/2687
Date:
21 Oct 2021
Publisher:
CDS
Description:
Using multiwavelength data, from ultraviolet to optical to near-infrared to mid-infrared, for ~6000 galaxies in the local Universe, we study the dependence of star formation on the morphological T-types for massive galaxies (logM*/M_{sun}_>=10). We find that, early-type spirals (Sa-Sbc) and S0s predominate in the green valley, which is a transition zone between the star forming and quenched regions. Within the early-type spirals, as we move from Sa to Sbc spirals the fraction of green valley and quenched galaxies decreases, indicating the important role of the bulge in the quenching of galaxies. The fraction of early-type spirals decreases as we enter the green valley from the blue cloud, which coincides with the increase in the fraction of S0s. These points towards the morphological transformation of early-type spiral galaxies into S0s, which can happen due to environmental effects such as ram-pressure stripping, galaxy harassment or tidal interactions. We also find a second population of S0s that are actively star forming and are present in all environments. Since morphological T-type, specific star formation rate (sSFR), and environmental density are all correlated with each other, we compute the partial correlation coefficient for each pair of parameters while keeping the third parameter as a control variable. We find that morphology most strongly correlates with sSFR, independent of the environment, while the other two correlations (morphology-density and sSFR-environment) are weaker. Thus, we conclude that, for massive galaxies in the local Universe, the physical processes that shape their morphology are also the ones that determine their star-forming state.
2188. Massive galaxies in CANDELS-UDS field
ID:
ivo://CDS.VizieR/J/MNRAS/427/1666
Title:
Massive galaxies in CANDELS-UDS field
Short Name:
J/MNRAS/427/1666
Date:
21 Oct 2021
Publisher:
CDS
Description:
We have used high-resolution, Hubble Space Telescope, near-infrared imaging to conduct a detailed analysis of the morphological properties of the most massive galaxies at high redshift, modelling the WFC3/IR H_160_-band images of the =~200 galaxies in the CANDELS-UDS field with photometric redshifts 1<z<3, and stellar masses M_*_>10^11^M_{sun}_. We have explored the results of fitting single-Sersic and bulge+disc models, and have investigated the additional errors and potential biases introduced by uncertainties in the background and the on-image point spread function.
2189. Massive galaxies in Extended Groth Strip
ID:
ivo://CDS.VizieR/J/MNRAS/382/109
Title:
Massive galaxies in Extended Groth Strip
Short Name:
J/MNRAS/382/109
Date:
21 Oct 2021
Publisher:
CDS
Description:
Using the combined capabilities of the large near-infrared Palomar/DEEP-2 survey, and the superb resolution of the Advanced Camera for Surveys HST camera, we explore the size evolution of 831 very massive galaxies (M*>=10^11^h^-2^_70_M_{sun}_) since z~2. We split our sample according to their light concentration using the Sersic index n. At a given stellar mass, both low (n<2.5) and high (n>2.5) concentrated objects were much smaller in the past than their local massive counterparts. This evolution is particularly strong for the highly concentrated (spheroid like) objects. At z~1.5, massive spheroid-like objects were a factor of 4(+/-0.4) smaller (i.e. almost two orders of magnitudes denser) than those we see today. These small sized, high-mass galaxies do not exist in the nearby Universe, suggesting that this population merged with other galaxies over several billion years to form the largest galaxies we see today.
2190. Massive metal-poor galaxies from SDSS
ID:
ivo://CDS.VizieR/J/ApJ/695/259
Title:
Massive metal-poor galaxies from SDSS
Short Name:
J/ApJ/695/259
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present a sample of 42 high-mass low-metallicity outliers from the mass-metallicity relation of star-forming galaxies. These galaxies have stellar masses that span log(M_*_/M_{sun}_)~9.4 to 11.1 and are offset from the mass-metallicity relation by -0.3 to -0.85dex in 12+log(O/H). In general, they are extremely blue, have high star-formation rates for their masses, and are morphologically disturbed. Tidal interactions are expected to induce large-scale gas inflow to the galaxies' central regions, and we find that these galaxies' gas-phase oxygen abundances are consistent with large quantities of low-metallicity gas from large galactocentric radii diluting the central metal-rich gas. We conclude with implications for deducing gas-phase metallicities of individual galaxies based solely on their luminosities, specifically in the case of long gamma-ray burst host galaxies.

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