459 research outputs found
The Stripe 82 Massive Galaxy Project III: A Lack of Growth Among Massive Galaxies
The average stellar mass (Mstar) of high-mass galaxies (Mstar > 3e11 Msun) is
expected to grow by ~30% since z~1, largely through ongoing mergers that are
also invoked to explain the observed increase in galaxy sizes. Direct evidence
for the corresponding growth in stellar mass has been elusive, however, in part
because the volumes sampled by previous redshift surveys have been too small to
yield reliable statistics. In this work, we make use of the Stripe 82 Massive
Galaxy Catalog to build a mass-limited sample of 41,770 galaxies (Mstar >
1.6e11) with optical to near-IR photometry and a large fraction (>55%) of
spectroscopic redshifts. Our sample spans 139 square degrees, significantly
larger than most previous efforts. After accounting for a number of potential
systematic errors, including the effects of Mstar scatter, we measure galaxy
stellar mass functions over 0.3 < z < 0.65 and detect no growth in the typical
Mstar of massive galaxies with an uncertainty of 9%. This confidence level is
dominated by uncertainties in the star formation history assumed for Mstar
estimates, although our inability to characterize low surface-brightness
outskirts may be the most important limitation of our study. Even among these
high-mass galaxies, we find evidence for differential evolution when splitting
the sample by recent star formation (SF) activity. While low-SF systems appear
to become completely passive, we find a mostly sub-dominant population of
galaxies with residual, but low rates of star formation (~1 Msun/yr) number
density does not evolve. Interestingly, these galaxies become more prominent at
higher Mstar, representing ~10% of all galaxies at Mstar ~ 1e12 Msun and
perhaps dominating at even larger masses.Comment: Accepted in Ap
A 2.5% measurement of the growth rate from small-scale redshift space clustering of SDSS-III CMASS galaxies
We perform the first fit to the anisotropic clustering of SDSS-III CMASS DR10
galaxies on scales of ~ 0.8 - 32 Mpc/h. A standard halo occupation distribution
model evaluated near the best fit Planck LCDM cosmology provides a good fit to
the observed anisotropic clustering, and implies a normalization for the
peculiar velocity field of M ~ 2 x 10^13 Msun/h halos of f*sigma8(z=0.57) =
0.450 +/- 0.011. Since this constraint includes both quasi-linear and
non-linear scales, it should severely constrain modified gravity models that
enhance pairwise infall velocities on these scales. Though model dependent, our
measurement represents a factor of 2.5 improvement in precision over the
analysis of DR11 on large scales, f*sigma8(z=0.57) = 0.447 +/- 0.028, and is
the tightest single constraint on the growth rate of cosmic structure to date.
Our measurement is consistent with the Planck LCDM prediction of 0.480 +/-
0.010 at the ~1.9 sigma level. Assuming a halo mass function evaluated at the
best fit Planck cosmology, we also find that 10% of CMASS galaxies are
satellites in halos of mass M ~ 6 x 10^13 Msun/h. While none of our tests and
model generalizations indicate systematic errors due to an insufficiently
detailed model of the galaxy-halo connection, the precision of these first
results warrant further investigation into the modeling uncertainties and
degeneracies with cosmological parameters.Comment: 24 pages, 20 figures, submitted to MNRAS. v2 is 27 pages, 23 figures,
accepted by MNRA
Lensing without borders - I. A blind comparison of the amplitude of galaxy-galaxy lensing between independent imaging surveys
ArtÃculo escrito por un elevado número de autores, solo se referencian el que aparece en primer lugar, los autores pertenecientes a la UAM y el nombre del grupo de colaboración, si lo hubiereThis is a pre-copyedited, author-produced PDF of an article accepted for publication in Monthly Notices of the Royal Astronomical Society following peer review. The version of record Monthly Notices of the Royal Astronomical Society 510.4 (2022): 6150-6189 is available online at: https://academic.oup.com/mnras/article-abstract/510/4/6150/6461104?redirectedFrom=fulltext#no-access-messageLensing without borders is a cross-survey collaboration created to assess the consistency of galaxy–galaxy lensing signals (ΔΣ) across different data sets and to carry out end-to-end tests of systematic errors. We perform a blind comparison of the amplitude of ΔΣ using lens samples from BOSS and six independent lensing surveys. We find good agreement between empirically estimated and reported systematic errors which agree to better than 2.3σ in four lens bins and three radial ranges. For lenses with zL > 0.43 and considering statistical errors, we detect a 3–4σ correlation between lensing amplitude and survey depth. This correlation could arise from the increasing impact at higher redshift of unrecognized galaxy blends on shear calibration and imperfections in photometric redshift calibration. At zL > 0.54, amplitudes may additionally correlate with foreground stellar density. The amplitude of these trends is within survey-defined systematic error budgets that are designed to include known shear and redshift calibration uncertainty. Using a fully empirical and conservative method, we do not find evidence for large unknown systematics. Systematic errors greater than 15 per cent (25 per cent) ruled out in three lens bins at 68 per cent (95 per cent) confidence at z < 0.54. Differences with respect to predictions based on clustering are observed to be at the 20–30 per cent level. Our results therefore suggest that lensing systematics alone are unlikely to fully explain the ‘lensing is low’ effect at z < 0.54. This analysis demonstrates the power of cross-survey comparisons and provides a promising path for identifying and reducing systematics in future lensing analyse
The effect of Warm Dark Matter on galaxy properties: constraints from the stellar mass function and the Tully-Fisher relation
In this paper we combine high resolution N-body simulations with a semi
analytical model of galaxy formation to study the effects of a possible Warm
Dark Matter (WDM) component on the observable properties of galaxies. We
compare three WDM models with a dark matter mass of 0.5, 0.75 and 2.0 keV, with
the standard Cold Dark Matter case. For a fixed set of parameters describing
the baryonic physics the WDM models predict less galaxies at low (stellar)
masses, as expected due to the suppression of power on small scales, while no
substantial difference is found at the high mass end. However these differences
in the stellar mass function, vanish when different set of parameters are used
to describe the (largely unknown) galaxy formation processes. We show that is
possible to break this degeneracy between DM properties and the
parameterization of baryonic physics by combining observations on the stellar
mass function with the Tully-Fisher relation (the relation between stellar mass
and the rotation velocity at large galactic radii as probed by resolved HI
rotation curves). WDM models with a too warm candidate (m<0.75 keV) cannot
simultaneously reproduce the stellar mass function and the Tully-Fisher
relation. We conclude that accurate measurements of the galaxy stellar mass
function and the link between galaxies and dark matter haloes down to the very
low-mass end can give very tight constraints on the nature of DM candidates.Comment: 8 pages, 5 figures, minor changes, accepted for publication on Ap
Galaxy-Mass Correlations on 10 Mpc Scales in the Deep Lens Survey
We examine the projected correlation of galaxies with mass from small scales
(<few hundred kpc) where individual dark matter halos dominate, out to 15 Mpc
where correlated large-scale structure dominates. We investigate these profiles
as a function of galaxy luminosity and redshift. Selecting 0.8 million galaxies
in the Deep Lens Survey, we use photometric redshifts and stacked weak
gravitational lensing shear tomography out to radial scales of 1 degree from
the centers of foreground galaxies. We detect correlated mass density from
multiple halos and large-scale structure at radii larger than the virial
radius, and find the first observational evidence for growth in the galaxy-mass
correlation on 10 Mpc scales with decreasing redshift and fixed range of
luminosity. For a fixed range of redshift, we find a scaling of projected halo
mass with rest-frame luminosity similar to previous studies at lower redshift.
We control systematic errors in shape measurement and photometric redshift,
enforce volume completeness through absolute magnitude cuts, and explore
residual sample selection effects via simulations.Comment: 13 pages, 9 figures, re-submitted to ApJ after addressing referee
comment
Sumo Puff: Tidal Debris or Disturbed Ultra-Diffuse Galaxy?
We report the discovery of a diffuse stellar cloud with an angular extent
, which we term "Sumo Puff", in data from the Hyper
Suprime-Cam Subaru Strategic Program (HSC-SSP). While we do not have a redshift
for this object, it is in close angular proximity to a post-merger galaxy at
redshift and is projected within a few virial radii (assuming
similar redshifts) of two other galaxies, which we use to
bracket a potential redshift range of . The object's light
distribution is flat, as characterized by a low Sersic index (). It
has a low central -band surface brightness of mag
arcsec, large effective radius of (
kpc at and kpc at ), and an elongated
morphology (). Its red color () is consistent with a
passively evolving stellar population and similar to the nearby post-merger
galaxy, and we may see tidal material connecting Sumo Puff with this galaxy. We
offer two possible interpretations for the nature of this object: (1) it is an
extreme, galaxy-size tidal feature associated with a recent merger event, or
(2) it is a foreground dwarf galaxy with properties consistent with a quenched,
disturbed ultra-diffuse galaxy. We present a qualitative comparison with
simulations that demonstrates the feasibility of forming a structure similar to
this object in a merger event. Follow-up spectroscopy and/or deeper imaging to
confirm the presence of the bridge of tidal material will be necessary to
reveal the true nature of this object.Comment: 10 pages, 5 figures, submitted to PASJ for the HSC-SSP special issu
Evolution of the Stellar-to-Dark Matter relation: separating star-forming and passive galaxies from z = 1 to 0
We use measurements of the stellar mass function, galaxy clustering, and galaxy-galaxy lensing within the COSMOS survey to constrain the stellar-to-halo mass relation (SHMR) of star forming and quiescent galaxies over the redshift range z = [0.2, 1.0]. For massive galaxies, M * gsim 1010.6 M ☉, our results indicate that star-forming galaxies grow proportionately as fast as their dark matter halos while quiescent galaxies are outpaced by dark matter growth. At lower masses, there is minimal difference in the SHMRs, implying that the majority low-mass quiescent galaxies have only recently been quenched of their star formation. Our analysis also affords a breakdown of all COSMOS galaxies into the relative numbers of central and satellite galaxies for both populations. At z = 1, satellite galaxies dominate the red sequence below the knee in the stellar mass function. But the number of quiescent satellites exhibits minimal redshift evolution; all evolution in the red sequence is due to low-mass central galaxies being quenched of their star formation. At M * ~ 1010 M ☉, the fraction of central galaxies on the red sequence increases by a factor of 10 over our redshift baseline, while the fraction of quenched satellite galaxies at that mass is constant with redshift. We define a "migration rate" to the red sequence as the time derivative of the passive galaxy abundances. We find that the migration rate of central galaxies to the red sequence increases by nearly an order of magnitude from z = 1 to z = 0. These results imply that the efficiency of quenching star formation for centrals is increasing with cosmic time, while the mechanisms that quench the star formation of satellite galaxies in groups and clusters is losing efficiency
- …