Abstract
We present a measurement of the Hubble constant
H
0
from surface brightness fluctuation (SBF) distances for 63 bright, mainly early-type galaxies out to 100 Mpc observed with the WFC3/IR on ...the Hubble Space Telescope (HST). The sample is drawn from several independent HST imaging programs using the F110W bandpass, with the majority of the galaxies being selected from the MASSIVE survey. The distances reach the Hubble flow with a median statistical uncertainty per measurement of 4%. We construct the Hubble diagram with these IR SBF distances and constrain
H
0
using four different treatments of the galaxy velocities. For the SBF zero-point calibration, we use both the existing tie to Cepheid variables, updated for consistency with the latest determination of the distance to the Large Magellanic Cloud from detached eclipsing binaries, and a new tie to the tip of the red giant branch (TRGB) calibrated from the maser distance to NGC 4258. These two SBF calibrations are consistent with each other and with theoretical predictions from stellar population models. From a weighted average of the Cepheid and TRGB calibrations, we derive
H
0
= 73.3 ± 0.7 ± 2.4 km s
−1
Mpc
−1
, where the error bars reflect the statistical and systematic uncertainties. This result accords well with recent measurements of
H
0
from Type Ia supernovae, time delays in multiply lensed quasars, and water masers. The systematic uncertainty could be reduced to below 2% by calibrating the SBF method with precision TRGB distances for a statistical sample of massive early-type galaxies out to the Virgo cluster measured with the James Webb Space Telescope.
The ACS Virgo Cluster Survey consists of HST ACS imaging for 100 early-type galaxies in the Virgo Cluster, observed in the F475W (-SDSS g) and F850LP (-SDSS z) filters. We derive distances for 84 of ...these galaxies using the method of surface brightness fluctuations (SBFs), present the SBF distance catalog, and use this database to examine the three-dimensional distribution of early-type galaxies in the Virgo Cluster. The SBF distance moduli have a mean (random) measurement error of 0.07 mag (0.5 Mpc), or roughly 3 times better than previous SBF measurements for Virgo Cluster galaxies. Five galaxies lie at a distance of d - 23 Mpc and are members of the W' cloud. The remaining 79 galaxies have a narrow distribution around our adopted distance of < d > = 16.5 c0.1 (random mean error) c1.1 Mpc (systematic). The rms distance scatter of this sample is s(d) = 0.6 c0.1 Mpc, with little or no dependence on morphological type or luminosity class (i.e., 0.7 c0.1 and 0.5 c0.1 Mpc for the giants and dwarfs, respectively). The back-to-front depth of the cluster measured from our sample of early-type galaxies is 2.4 c 0.4 Mpc (i.e., c2 s of the intrinsic distance distribution). The M87 (cluster A) and M49 (cluster B) subclusters are found to lie at distances of 16.7 c 0.2 and 16.4 c 0.2 Mpc, respectively. There may be a third subcluster associated with M86. A weak correlation between velocity and line-of-sight distance may be a faint echo of the cluster velocity distribution not having yet completely virialized. In three dimensions, Virgo's early-type galaxies appear to define a slightly triaxial distribution, with axis ratios of (1: 0.7: 0.5). The principal axis of the best-fit ellipsoid is inclined 620-40 from the line of sight, while the galaxies belonging to the W' cloud lie on an axis inclined by 610-15.
Massive early-type galaxies represent the modern day remnants of the earliest major star formation episodes in the history of the universe. These galaxies are central to our understanding of the ...evolution of cosmic structure, stellar populations, and supermassive black holes, but the details of their complex formation histories remain uncertain. To address this situation, we have initiated the MASSIVE Survey, a volume-limited, multi-wavelength, integral-field spectroscopic (IFS) and photometric survey of the structure and dynamics of the ~100 most massive early-type galaxies within a distance of 108 Mpc. This survey probes a stellar mass range M* gap 10 super(11.5) M sub(middot in circle) and diverse galaxy environments that have not been systematically studied to date. Our wide-field IFS data cover about two effective radii of individual galaxies, and for a subset of them, we are acquiring additional IFS observations on sub-arcsecond scales with adaptive optics. We are also acquiring deep K-band imaging to trace the extended halos of the galaxies and measure accurate total magnitudes. Dynamical orbit modeling of the combined data will allow us to simultaneously determine the stellar, black hole, and dark matter halo masses. The primary goals of the project are to constrain the black hole scaling relations at high masses, investigate systematically the stellar initial mass function and dark matter distribution in massive galaxies, and probe the late-time assembly of ellipticals through stellar population and kinematical gradients. In this paper, we describe the MASSIVE sample selection, discuss the distinct demographics and structural and environmental properties of the selected galaxies, and provide an overview of our basic observational program, science goals and early survey results.
We present spatially resolved two-dimensional stellar kinematics for the 41 most massive early-type galaxies (ETGs; M sub( K) ... -25.7 mag, stellar mass M* ... 10 super( 11.8) M...) of the ...volume-limited (D < 108 Mpc) MASSIVE survey. For each galaxy, we obtain high-quality spectra in the wavelength range of 3650-5850 A from the 246-fibre Mitchell integral-field spectrograph at McDonald Observatory, covering a 107 arcsec x 107 arcsec field of view (often reaching 2 to 3 effective radii). We measure the 2D spatial distribution of each galaxy's angular momentum (... and fast or slow rotator status), velocity dispersion (...), and higher order non-Gaussian velocity features (Gauss-Hermite moments h sub( 3) to h sub( 6)). Our sample contains a high fraction (~80 per cent) of slow and non-rotators with ... 0.2. When combined with the lower mass ETGs in the ATLAS super( 3D) survey, we find the fraction of slow rotators to increase dramatically with galaxy mass, reaching ~50 per cent at M sub( K) ~ -25.5 mag and ~90 per cent at M sub( K) ... -26 mag. All of our fast rotators show a clear anticorrelation between h sub( 3) and ..., and the slope of the anticorrelation is steeper in more round galaxies. The radial profiles of ... show a clear luminosity and environmental dependence: the 12 most luminous galaxies in our sample (M sub( K) ... -26 mag) are all brightest cluster/group galaxies (except NGC 4874) and all have rising or nearly flat ... profiles, whereas five of the seven 'isolated' galaxies are all fainter than M sub( K) = -25.8 mag and have falling ... All of our galaxies have positive average h sub( 4); the most luminous galaxies have average h sub( 4) ~ 0.05, while less luminous galaxies have a range of values between 0 and 0.05. Most of our galaxies show positive radial gradients in h sub( 4), and those galaxies also tend to have rising ... profiles. We discuss the implications for the relationship among dynamical mass, ..., h sub( 4), and velocity anisotropy for these massive galaxies. (ProQuest: ... denotes formulae/symbols omitted.)
Abstract
We analyse the environmental properties of 370 local early-type galaxies (ETGs) in the MASSIVE and ATLAS3D surveys, two complementary volume-limited integral-field spectroscopic (IFS) galaxy ...surveys spanning absolute K-band magnitude − 21.5 ≳ MK
≳ −26.6, or stellar mass
$8\times 10^{9} \lesssim M_* \lesssim 2\times 10^{12}\,\text{M}_{\odot }$
. We find these galaxies to reside in a diverse range of environments measured by four methods: group membership (whether a galaxy is a brightest group/cluster galaxy, satellite or isolated), halo mass, large-scale mass density (measured over a few Mpc) and local mass density (measured within the Nth neighbour). The spatially resolved IFS stellar kinematics provide robust measurements of the spin parameter λe and enable us to examine the relationship among λe, M
* and galaxy environment. We find a strong correlation between λe and M
*, where the average λe decreases from ∼0.4 to below 0.1 with increasing mass, and the fraction of slow rotators f
slow increase from ∼10 to 90 per cent. We show for the first time that at fixed M
*, there are almost no trends between galaxy spin and environment; the apparent kinematic morphology–density relation for ETGs is therefore primarily driven by M
* and is accounted for by the joint correlations between M
* and spin, and between M
* and environment. A possible exception is that the increased f
slow at high local density is slightly more than expected based only on these joint correlations. Our results suggest that the physical processes responsible for building up the present-day stellar masses of massive galaxies are also very efficient at reducing their spin, in any environment.
We describe a program to measure surface brightness fluctuation (SBF) distances to galaxies observed in the Next Generation Virgo Cluster Survey (NGVS), a photometric imaging survey covering 104 deg2 ...of the Virgo cluster in the u*, g, i, and z bandpasses with the Canada-France-Hawaii Telescope. We describe the selection of the sample galaxies, the procedures for measuring the apparent i-band SBF magnitude , and the calibration of the absolute as a function of observed stellar population properties. The multiband NGVS data set provides multiple options for calibrating the SBF distances, and we explore various calibrations involving individual color indices as well as combinations of two different colors. Within the color range of the present sample, the two-color calibrations do not significantly improve the scatter with respect to wide-baseline, single-color calibrations involving u*. We adopt the calibration as a reference for the present galaxy sample, with an observed scatter of 0.11 mag. For a few cases that lack good u* photometry, we use an alternative relation based on a combination of and colors, with only a slightly larger observed scatter of 0.12 mag. The agreement of our measurements with the best existing distance estimates provides confidence that our measurements are accurate. We present a preliminary catalog of distances for 89 galaxies brighter than BT 13.0 mag within the survey footprint, including members of the background M and W Clouds at roughly twice the distance of the main body of the Virgo cluster. The extension of the present work to fainter and bluer galaxies is in progress.
ABSTRACT Studies of the physical properties of local elliptical galaxies are shedding new light on galaxy formation. Here we present the hot-gas properties of 33 early-type systems within the MASSIVE ...galaxy survey that have archival Chandra X-ray observations, and we use these data to derive X-ray luminosities ( ) and plasma temperatures ( ) for the diffuse gas components. We combine this with the survey to investigate the X-ray-optical properties of a statistically significant sample of early-type galaxies across a wide range of environments. When X-ray measurements are performed consistently in apertures set by the galaxy stellar content, we deduce that all early types (independent of galaxy mass, environment, and rotational support) follow a universal scaling law such that . We further demonstrate that the scatter in around both K-band luminosity (LK) and the galaxy stellar velocity dispersion ( ) is primarily driven by , with no clear trends with halo mass, radio power, or angular momentum of the stars. It is not trivial to tie the gas origin directly to either stellar mass or galaxy potential. Indeed, our data require a steeper relation between , and than predicted by standard mass-loss models. Finally, we find that is set by the galaxy potential inside the optical effective radius. We conclude that within the innermost 10-30 kpc region, early types maintain pressure-supported hot gas, with a minimum set by the virial temperature, but the majority show evidence for additional heating.
The Advanced Camera for Surveys (ACS) Fornax Cluster Survey is a Hubble Space Telescope program to image 43 early-type galaxies in the Fornax cluster, using the F475W and F850LP bandpasses of the ...ACS. We employ both one-dimensional and two-dimensional techniques to characterize the properties of the stellar nuclei in these galaxies, defined as the central "luminosity excesses", relative to a Sersic model fitted to the underlying host. We find 72% + or - 13% of our sample (31 galaxies) to be nucleated, with only three of the nuclei offset by more than 0".5 from their galaxy photocenter, and with the majority of nuclei having colors bluer than their hosts. The nuclei are observed to be larger, and brighter, than typical Fornax globular clusters and to follow different structural scaling relations. A comparison of our results to those from the ACS Virgo Cluster Survey reveals striking similarities in the properties of the nuclei belonging to these different environments. We briefly review a variety of proposed formation models and conclude that, for the low-mass galaxies in our sample, the most important mechanism for nucleus growth is probably infall of star clusters through dynamical friction, while for higher mass galaxies, gas accretion triggered by mergers, accretions, and tidal torques is likely to dominate, with the relative importance of these two processes varying smoothly as a function of galaxy mass. Some intermediate-mass galaxies in our sample show a complexity in their inner structure that may be the signature of the "hybrid nuclei" that arose through parallel formation channels.
ABSTRACT We examine stellar population gradients in ∼100 massive early-type galaxies spanning km s−1 and MK of −22.5 to −26.5 mag, observed as part of the MASSIVE survey. Using integral-field ...spectroscopy from the Mitchell Spectrograph on the 2.7 m telescope at McDonald Observatory, we create stacked spectra as a function of radius for galaxies binned by their stellar velocity dispersion, stellar mass, and group richness. With excellent sampling at the highest stellar mass, we examine radial trends in stellar population properties extending to beyond twice the effective radius ( ). Specifically, we examine trends in age, metallicity, and abundance ratios of Mg, C, N, and Ca, and discuss the implications for star formation histories and elemental yields. At a fixed physical radius of 3-6 kpc (the likely size of the galaxy cores formed at high redshift), stellar age and /Fe increase with increasing and depend only weakly on stellar mass, as we might expect if denser galaxies form their central cores earlier and faster. If we instead focus on , the trends in abundance and abundance ratio are washed out, as might be expected if the stars at large radius were accreted by smaller galaxies. Finally, we show that when controlling for , there are only very subtle differences in stellar population properties or gradients as a function of group richness; even at large radius, internal properties matter more than environment in determining star formation history.
The total mass in the globular cluster (GC) system of a galaxy is empirically a near-constant fraction of the total mass of the galaxy across a range of 105 in galaxy mass. This trend is radically ...unlike the strongly nonlinear behavior of total stellar mass M versus Mh. We discuss extensions of this trend to two more extreme situations: (a) entire clusters of galaxies and (b) the ultra-diffuse galaxies (UDGs) recently discovered in Coma and elsewhere. Our calibration of the ratio from normal galaxies, accounting for new revisions in the adopted mass-to-light ratio for GCs, now gives as the mean absolute mass fraction. We find that the same ratio appears valid for galaxy clusters and UDGs. Estimates of in the four clusters we examine tend to be slightly higher than for individual galaxies, but more data and better constraints on the mean GC mass in such systems are needed to determine if this difference is significant. We use the constancy of to estimate total masses for several individual cases; for example, the total mass of the Milky Way is calculated to be . Physical explanations for the uniformity of are still descriptive, but point to a picture in which massive dense star clusters in their formation stages were relatively immune to the feedback that more strongly influenced lower-density regions where most stars form.
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