Monique C. Aller

• Professor (Assistant) at Georgia Southern University

Gas flows in and out of galaxies through their circum-galactic medium (CGM) are poorly constrained and direct observations of this faint, diffuse medium remain challenging. We use a sample of five z ~ 1-2 galaxy counterparts to damped Lyman-α absorbers (DLAs) to combine data on cold gas, metals and stellar content of the same galaxies. We present n...

Gas flows in and out of galaxies through their circumgalactic medium (CGM) are poorly constrained and direct observations of this faint, diffuse medium remain challenging. We use a sample of five $z$ $\sim$ 1-2 galaxy counterparts to Damped Lyman-$\alpha$ Absorbers (DLAs) to combine data on cold gas, metals and stellar content of the same galaxies....

This article is based on an invited talk given by V. P. Kulkarni at the 8th Cosmic Dust meeting. Dust has a profound effect on the physics and chemistry of the interstellar gas in galaxies and on the appearance of galaxies. Understanding the cosmic evolution of dust with time is therefore crucial for understanding the evolution of galaxies. Despite...

This article is based on an invited talk given by V.P. Kulkarni at the 8th Cosmic Dust meeting. Dust has a profound effect on the physics and chemistry of the interstellar gas in galaxies and on the appearance of galaxies. Understanding the cosmic evolution of dust with time is therefore crucial for understanding the evolution of galaxies. Despite...

Gas and dust grains are fundamental components of the interstellar medium and significantly impact many of the physical processes driving galaxy evolution, such as star-formation, and the heating, cooling, and ionization of the interstellar material. Quasar absorption systems (QASs), which trace intervening galaxies along the sightlines to luminous...

We report observations of four sub-damped Lyman-alpha (sub-DLA) quasar absorbers at z<0.5 obtained with the Hubble Space Telescope Cosmic Origins Spectrograph. We measure the available neutrals or ions of C, N, O, Si, P, S, Ar, Mn, Fe, and/or Ni. Our data have doubled the sub-DLA metallicity samples at z<0.5 and improved constraints on sub-DLA chem...

Absorption lines in the spectra of distant quasars whose sightlines pass through foreground galaxies provide a valuable tool to probe the dust and gas compositions of the interstellar medium (ISM) in galaxies. The first evidence of silicate dust in a quasar absorption system (QAS) was provided through our detection of the 10 micron silicate feature...

We report the detection of interstellar silicate dust in the z abs = 0.685 absorber along the sightline toward the gravitationally lensed blazar TXS 0218+357. Using Spitzer Space Telescope Infrared Spectrograph data, we detect the 10 μm silicate absorption feature with a detection significance of 10.7σ. We fit laboratory-derived silicate dust profi...

Interstellar dust plays a significant role in the physical processes driving galaxy evolution, such as star-formation, and the heating, cooling, and ionization of interstellar material. While interstellar dust has been studied extensively in local galaxies, much less is known about the properties of dust grains in distant galaxies. One technique to...

We present evidence of a >10-sigma detection of the 10 micron silicate dust absorption feature in the spectrum of the gravitationally lensed quasar PKS 1830-211, produced by a foreground absorption system at redshift 0.886. We have examined more than 100 optical depth templates, derived from both observations of Galactic and extragalactic sources a...

We present a study of the multi-wavelength properties, from the mid-infrared to the hard X-rays, of a sample of 255 spectroscopically identified X-ray selected Type-2 AGN from the XMM-COSMOS survey. Most of them are obscured the X-ray absorbing column density is determined by either X-ray spectral analyses (for the 45% of the sample), or from hardn...

We explore the connection between black hole growth at the center of obscured quasars selected from the XMM-COSMOS survey and the physical properties of their host galaxies. We study a bolometric regime ( 8 x 10^45 erg/s) where several theoretical models invoke major galaxy mergers as the main fueling channel for black hole accretion. We confirm th...

Polar ring galaxies (PRGs) are visually spectacular objects, consisting of a robustly star forming ring of gas, dust and stars orbiting a plane perpendicular to the major axis of a central S0. Since the ring material experiences the gravitational potential in the polar plane, PRGs offer unique probes of the shapes of the dark matter halo. Furthermo...

We investigate the (large-scale) bar fraction in a mass-complete sample of M > 10^(10.5) M_⊙ disc galaxies at 0.2 < z < 0.6 in the Cosmological Evolution Survey (COSMOS) field. The fraction of barred discs strongly depends on mass, disc morphology and specific star formation rate (SSFR). At intermediate stellar mass (10^(10.5) < M < 10^(11) M_⊙) th...

We use ~8600 COSMOS galaxies at mass scales >5 × 1010M ? to study how the morphological mix of massive ellipticals, bulge-dominated disks, intermediate-bulge disks, disk-dominated galaxies, and irregular systems evolves from z = 0.2 to z = 1. The morphological evolution depends strongly on mass. At M > 3 × 1011M ?, no evolution is detected in the m...

Using Chandra observations we have identified a sample of seven off-nuclear X-ray sources, in the redshift range z=0.072-0.283, located within optically bright galaxies in the COSMOS Survey. Using the multi-wavelength coverage available in the COSMOS field, we study the properties of the host galaxies of these ULXs. In detail, we derived their star...

We use ~8,600 >5e10 Msol COSMOS galaxies to study how the morphological mix of massive ellipticals, bulge-dominated disks, intermediate-bulge disks, bulge-less disks and irregular galaxies evolves from z=0.2 to z=1. The morphological evolution depends strongly on mass. At M>3e11 Msol, no evolution is detected in the morphological mix: ellipticals d...

We derive improved versions of the relations between supermassive black hole mass (M BH) and host-galaxy bulge velocity dispersion (σ) and luminosity (L; the M-σ and M-L relations), based on 49 M BH measurements and 19 upper limits. Particular attention is paid to recovery of the intrinsic scatter (0) in both relations. We find log(M BH/M ☉) = α +...

We report five new measurements of central black hole masses based on Space Telescope Imaging Spectrograph and Wide Field Planetary Camera 2 observations with the Hubble Space Telescope (HST) and on axisymmetric, three-integral, Schwarzschild orbit-library kinematic models. We selected a sample of galaxies within a narrow range in velocity dispersi...

We determine the mass of the black hole at the center of the spiral galaxy NGC 4258 by constructing axisymmetric dynamical models of the galaxy. These models are constrained by high spatial resolution imaging and long-slit spectroscopy of the nuclear region obtained with the Hubble Space Telescope, complemented by ground-based observations extendin...

We report five new measurements of central black hole masses based on STIS and WFPC2 observations with the Hubble Space Telescope and on axisymmetric, three-integral, Schwarzschild orbit-library kinematic models. We selected a sample of galaxies within a narrow range in velocity dispersion that cover a range of galaxy parameters (including Hubble t...

We combine several HST investigations on the central structure of early-type galaxies to generate a large sample of surface photometry. The studies selected were those that used the "Nuker law" to characterize the inner light distributions of the galaxies. The sample comprises WFPC1 and WFPC2 V-band observations published earlier by our group, R-ba...

The largest galaxies, and in particular central galaxies in clusters, offer unique insight into understanding the mechanism for the growth of nuclear black holes. We present Hubble Space Telescope kinematics for NGC 1399, the central galaxy in Fornax. We find the best-fit model contains a black hole of (5.1 ± 0.7) × 108 M☉ (at a distance of 21.1 Mp...

We analyze HST+WFPC2 images of 77 early-type galaxies. Brightness profiles are classed into "core" or "power-law" forms. Cores are typically rounder than power-law galaxies. Nearly all power-laws with central ellipticity >=0.3 have stellar disks, implying that disks are present in power-laws with epsilon <0.3, but are not visible due to unfavorable...

A variety of host galaxy (bulge) parameters are examined in order to determine their predictive power in ascertaining the masses of the supermassive black holes (SMBH) at the centers of the galaxies. Based on a sample of 23 nearby galaxies, comprised of both elliptical galaxies and spiral/lenticular bulges, we identify a strong correlation between...

We combine the results from several HST investigations of the central structure of early-type galaxies to generate a large sample of parameterized surface photometry. The studies included were those that used the "Nuker law" to characterize the inner light distributions of the galaxies. The sample comprises WFPC1 and WFPC2 V band observations publi...

Black hole masses predicted from the Mbh-sigma relationship conflict with those predicted from the Mbh-L relationship for the most luminous galaxies, such as brightest cluster galaxies (BCGs). This is because stellar velocity dispersion, sigma, increases only weakly with L for BCGs and other giant ellipticals. The Mbh-L relationship predicts that t...

The mass of the supermassive black hole is found to be well correlated with the gravitational potential energy of the galaxy's bulge, with a scatter comparable to that seen in currently accepted relations such as M-sigma and M-Mbulge for the same sample of galaxies, taken from Tremaine, S. et al. 2002, ApJ, 574, 740. Although the scatter in these f...

One of the most interesting findings from the search for supermassive black holes (BH) has been the discovery of the M-σ relation, a remarkably tight correlation between BH mass and the velocity dispersion of the stars in the galactic bulge outside of the BH ``sphere of influence''. The M-σ relation has a scatter which is < 0.3 dex in M, and consi...

We analyze HST+WFPC2 images of 77 early-type galaxies. Brightness profiles are classed into "core" or "power-law" forms. Cores are typically rounder than power-law galaxies. Nearly all power-laws with central ellipticity >=0.3 have stellar disks, implying that disks are present in power-laws with epsilon <0.3, but are not visible due to unfavorable...

We show that orbit-superposition dynamical models (Schwarzschild's method) provide reliable estimates of nuclear black hole masses and errors when constructed from adequate orbit libraries and kinematic data. We thus rebut two recent papers that argue that BH masses obtained from this method are unreliable. These papers claim to demonstrate that th...

The mass of the central supermassive black hole of the SAB(s)bc galaxy NGC 4258 is determined from stellar dynamical models which use superpositions of orbits to fit photometric and kinematic data. The data include ground-based and HST/NICMOS K-band photometry as well as ground-based long-slit and HST/STIS calcium triplet spectroscopy. The data are...

Supermassive black holes are thought to be relics of quasars, and their numbers and masses are therefore related to the quasar luminosity function and its evolution with redshift. We have used the relationship between black hole mass and bulge velocity dispersion (the M_bullet - sigma relation) to make an improved estimate of the mass density and m...

This project was inspired by optical and IR imaging suggesting that, while most QSO hosts at high z are too faint to detect, radio-loud quasars are hosted by exceptionally luminous galaxies. Thus, a search was undertaken for HI absorption against the continuum emission of strong radio emitters whose redshifts ( z ∼ 2.3) bring their HI line into the...

The ability of the upgraded Arecibo 305-m telescope to produce "quasi-instantaneous" radio continuum spectra covering over a decade of frequency has been investigated, the study being undertaken as an Arecibo Observatory summer-student observing project. Within the limits of early post-upgrade instrumentation and telescope performance, it was found...

Results from a multiwaveband study of the γ-ray-bright compact radio source 3C 454.3 are presented. © 1997 American Institute of Physics.

The blazar 3C 345 underwent a 2.5 mag optical outburst between 1990 November and 1991 May. We have obtained 10 nearly simultaneous multifrequency spectra during the course of the outburst in order to study the multifrequency spectral variations of 3C 345 as a function of time. Although our observations were not sampled frequently enough to complete...

Using a basic assumption that the bulge velocity dispersion of a galaxy can be used to predict the mass of its supermassive black hole, it is possible to estimate the mass density of black holes in the universe. Constructing the number density as a function of galaxy velocity dispersion from published data, an expression for the number density of b...

One of the most interesting findings from the search for supermassive black holes (BH) has been the discovery of the M-sigma relation, a remarkably tight correlation between BH mass and the velocity dispersion of the stars in the galactic bulge outside of the BH ``sphere of influence''. The M-sigma relation has a scatter which is < 0.3 dex in M, an...