18 research outputs found
The UVES Spectral Quasar Absorption Database (SQUAD) Data Release 1: The first 10 million seconds
We present the first data release (DR1) of the UVES Spectral Quasar
Absorption Database (SQUAD), comprising 467 fully reduced, continuum-fitted
high-resolution quasar spectra from the Ultraviolet and Visual Echelle
Spectrograph (UVES) on the European Southern Observatory's Very Large
Telescope. The quasars have redshifts -5, and a total exposure time of 10
million seconds provides continuum-to-noise ratios of 4-342 (median 20) per
2.5-km/s pixel at 5500 \AA. The SQUAD spectra are fully reproducible from the
raw, archival UVES exposures with open-source software, including our
UVES_popler tool for combining multiple extracted echelle exposures which we
document here. All processing steps are completely transparent and can be
improved upon or modified for specific applications. A primary goal of SQUAD is
to enable statistical studies of large quasar and absorber samples, and we
provide tools and basic information to assist three broad scientific uses:
studies of damped Lyman- systems (DLAs), absorption-line surveys and
time-variable absorption lines. For example, we provide a catalogue of 155 DLAs
whose Lyman- lines are covered by the DR1 spectra, 18 of which are
reported for the first time. The HI column densities of these new DLAs are
measured from the DR1 spectra. DR1 is publicly available and includes all
reduced data and information to reproduce the final spectra.Comment: 21 pages, 18 figures. Accepted by MNRAS. All final quasar spectra,
reduced contributing exposures, and supplementary material available via
https://github.com/MTMurphy77/UVES_SQUAD_DR
Supermassive black holes and their host Spheroids III. The Mbh-nsph Correlation
The Sérsic model is the best approximation known to date for describing the light distribution of stellar spheroidal and disk components, with the Sérsic index n providing a direct measure of the central radial concentration of stars. The Sérsic index of a galaxy's spheroidal component, nsph, has been shown to tightly correlate with the mass of the central supermassive black hole, MBH. The {M}_{\mathrm{BH}}\mbox{--}{n}_{\mathrm{sph}} correlation is also expected from other two well known scaling relations involving the spheroid luminosity, Lsph: the {L}_{\mathrm{sph}}\mbox{--}{n}_{\mathrm{sph}} and the {M}_{\mathrm{BH}}\mbox{--}{L}_{\mathrm{sph}}. Obtaining an accurate estimate of the spheroid Sérsic index requires a careful modeling of a galaxy's light distribution and some studies have failed to recover a statistically significant {M}_{\mathrm{BH}}\mbox{--}{n}_{\mathrm{sph}} correlation. With the aim of re-investigating the {M}_{\mathrm{BH}}\mbox{--}{n}_{\mathrm{sph}} and other black hole mass scaling relations, we performed a detailed (i.e., bulge, disks, bars, spiral arms, rings, halo, nucleus, etc.) decomposition of 66 galaxies, with directly measured black hole masses, that had been imaged at 3.6 μm with Spitzer. In this paper, the third of this series, we present an analysis of the {L}_{\mathrm{sph}}\mbox{--}{n}_{\mathrm{sph}} and {M}_{\mathrm{BH}}\mbox{--}{n}_{\mathrm{sph}} diagrams. While early-type (elliptical+lenticular) and late-type (spiral) galaxies split into two separate relations in the {L}_{\mathrm{sph}}\mbox{--}{n}_{\mathrm{sph}} and {M}_{\mathrm{BH}}\mbox{--}{L}_{\mathrm{sph}} diagrams, they reunite into a single sequence with relatively small intrinsic scatter (). The black hole mass appears to be closely related to the spheroid central concentration of stars, which mirrors the inner gradient of the spheroid gravitational potential
Supermassive black holes and their host spheroids. II. The red and blue sequence in the MBH–M*,SPH diagram
In our first paper, we performed a detailed (i.e., bulge, disks, bars, spiral arms, rings, halo, nucleus, etc.) decomposition of 66 galaxies, with directly measured black hole masses, MBH, imaged at with Spitzer. Our sample is the largest to date and, for the first time, the decompositions were checked for consistency with the galaxy kinematics. We present correlations between MBH and the host spheroid (and galaxy) luminosity, Lsph (and Lgal), and also stellar mass, While most previous studies have used galaxy samples that were overwhelmingly dominated by high-mass, early-type galaxies, our sample includes 17 spiral galaxies, half of which have and allows us to better investigate the poorly studied low-mass end of the correlation. The bulges of early-type galaxies follow and define a tight red sequence with intrinsic scatter and a median ratio of 0.68 ±0.04%, i.e., a range of 0.1%-5%. At the low-mass end, the bulges of late-type galaxies define a much steeper blue sequence, with and equal to at We additionally report that (1) our Sérsic galaxy sample follows a less steep sequence than previously reported; (2) bulges with Sérsic index argued by some to be pseudo-bulges, are not offset to lower MBH from the correlation defined by the current bulge sample with and (3) Lsph and Lgal correlate equally well with MBH, in terms of intrinsic scatter, only for early-type galaxies - once reasonable numbers of spiral galaxies are included, the correlation with Lsph is better than that with Lgal