Using the Spitzer Space Telescope and Herschel Space Observatory, we have
conducted a survey of infrared galaxies in the field of the galaxy cluster
Abell S1063 (AS1063) at $z=0.347$, which is one of ...the most massive clusters
known and a target of the HST CLASH and Frontier-Field surveys. The
Spitzer/MIPS 24 $\mu$m and Herschel/PACS & SPIRE images revealed that the core
of AS1063 is surprisingly devoid of infrared sources, showing only a few
detectable sources within the central r$\sim1^{\prime}$. There is, however, one
particularly bright source (2.3 mJy at 24 $\mu$m; 106 mJy at 160 $\mu$m), which
corresponds to a background galaxy at $z=0.61$. The modest magnification factor
(4.0$\times$) implies that this galaxy is intrinsically IR-luminous (L$_{\rm
IR}=3.1\times10^{11}\ \rm L_{\odot}$). What is particularly interesting about
this galaxy is that HST optical/near-infrared images show a remarkably bright
and large (1 kpc) clump at one edge of the disk. Our follow-up
optical/near-infrared spectroscopy shows Balmer (H$\alpha$-H8) and forbidden
emission from this clump (OII $\lambda$3727, OIII
$\lambda\lambda$4959,5007, NII $\lambda\lambda$6548,6583), indicating that it
is a HII region. The HII region appears to have formed in-situ, as
kinematically it is part of a rotating disk, and there is no evidence of nearby
interacting galaxies. With an extinction correction of A$_{\rm V}=1.5$ mag, the
star formation rate of this giant HII region is $\sim$10 M$_{\odot}$ yr$^{-1}$,
which is exceptionally large, even for high redshift HII regions. Such a large
and luminous HII region is often seen at $z\sim2$ but quite rare in the nearby
Universe.
We present accretion-disk structure measurements from continuum lags in the Sloan Digital Sky Survey Reverberation Mapping (SDSS-RM) project. Lags are measured using the \texttt{JAVELIN} software ...from the first-year SDSS-RM \(g\) and \(i\) photometry, resulting in well-defined lags for 95 quasars, 33 of which have lag SNR \(>\) 2\(\sigma\). We also estimate lags using the \texttt{ICCF} software and find consistent results, though with larger uncertainties. Accretion-disk structure is fit using a Markov Chain Monte Carlo approach, parameterizing the measured continuum lags as a function of disk size normalization, wavelength, black hole mass, and luminosity. In contrast with previous observations, our best-fit disk sizes and color profiles are consistent (within 1.5~\(\sigma\)) with the \citet{SS73} analytic solution. We also find that more massive quasars have larger accretion disks, similarly consistent with the analytic accretion-disk model. The data are inconclusive on a correlation between disk size and continuum luminosity, with results that are consistent with both no correlation and with the \citet{SS73} expectation. The continuum lag fits have a large excess dispersion, indicating that our measured lag errors are underestimated and/or our best-fit model may be missing the effects of orientation, spin, and/or radiative efficiency. We demonstrate that fitting disk parameters using only the highest-SNR lag measurements biases best-fit disk sizes to be larger than the disk sizes recovered using a Bayesian approach on the full sample of well-defined lags.
The Beijing-Arizona Sky Survey (BASS) is a wide and deep imaging survey to cover a 5400 deg\(^2\) area in the Northern Galactic Cap with the 2.3m Bok telescope using two filters (\(g\) and \(r\) ...bands). The Mosaic \(z\)-band Legacy Survey (MzLS) covers the same area in \(z\) band with the 4m Mayall telescope. These two surveys will be used for spectroscopic targeting of the Dark Energy Spectroscopic Instrument (DESI). The BASS survey observations were completed in 2019 March. This paper describes the third data release (DR3) of BASS, which contains the photometric data from all BASS and MzLS observations between 2015 January and 2019 March. The median astrometric precision relative to {\it Gaia} positions is about 17 mas and the median photometric offset relative to the PanSTARRS1 photometry is within 5 mmag. The median \(5\sigma\) AB magnitude depths for point sources are 24.2, 23.6, and 23.0 mag for \(g\), \(r\), and \(z\) bands, respectively. The photometric depth within the survey area is highly homogeneous, with the difference between the 20\% and 80\% depth less than 0.3 mag. The DR3 data, including raw data, calibrated single-epoch images, single-epoch photometric catalogs, stacked images, and co-added photometric catalogs, are publicly accessible at \url{http://batc.bao.ac.cn/BASS/doku.php?id=datarelease:home}.
We present a detailed characterization of the 849 broad-line quasars from the Sloan Digital Sky Survey Reverberation Mapping (SDSS-RM) project. Our quasar sample covers a redshift range of 0.1<z<4.5 ...and is flux-limited to i_PSF<21.7 without any other cuts on quasar properties. The main sample characterization includes: 1) spectral measurements of the continuum and broad emission lines for individual objects from the coadded first-season spectroscopy in 2014; 2) identification of broad and narrow absorption lines in the spectra; 3) optical variability properties for continuum and broad lines from multi-epoch spectroscopy. We provide improved systemic redshift estimates for all quasars, and demonstrate the effects of signal-to-noise ratio on the spectral measurements. We compile measured properties for all 849 quasars along with supplemental multi-wavelength data for subsets of our sample from other surveys. The SDSS-RM sample probes a diverse range in quasar properties, and shows well detected continuum and broad-line variability for many objects from first-season monitoring data. The compiled properties serve as the benchmark for follow-up work based on SDSS-RM data. The spectral fitting tools are made public along with this work.
This paper presents the second data release (DR2) of the Beijing-Arizona Sky Survey (BASS). BASS is an imaging survey of about 5400 deg\(^2\) in \(g\) and \(r\) bands using the 2.3 m Bok telescope. ...DR2 includes the observations as of July 2017 obtained by BASS and Mayall \(z\)-band Legacy Survey (MzLS). This is our first time to include the MzLS data covering the same area as BASS. BASS and MzLS have respectively completed about 72% and 76% of their observations. The two surveys will be served for the spectroscopic targeting of the upcoming Dark Energy Spectroscopic Instrument. Both BASS and MzLS data are reduced by the same pipeline. We have updated the basic data reduction and photometric methods in DR2. In particular, source detections are performed on stacked images, and photometric measurements are co-added from single-epoch images based on these sources. The median 5\(\sigma\) depths with corrections of the Galactic extinction are 24.05, 23.61, and 23.10 mag for \(g\), \(r\), and \(z\) bands, respectively. The DR2 data products include stacked images, co-added catalogs, and single-epoch images and catalogs. The BASS website (http://batc.bao.ac.cn/BASS/) provides detailed information and links to download the data.
Using the Spitzer Space Telescope and Herschel Space Observatory, we have conducted a survey of infrared galaxies in the field of the galaxy cluster Abell S1063 (AS1063) at \(z=0.347\), which is one ...of the most massive clusters known and a target of the HST CLASH and Frontier-Field surveys. The Spitzer/MIPS 24 \(\mu\)m and Herschel/PACS & SPIRE images revealed that the core of AS1063 is surprisingly devoid of infrared sources, showing only a few detectable sources within the central r\(\sim1^{\prime}\). There is, however, one particularly bright source (2.3 mJy at 24 \(\mu\)m; 106 mJy at 160 \(\mu\)m), which corresponds to a background galaxy at \(z=0.61\). The modest magnification factor (4.0\(\times\)) implies that this galaxy is intrinsically IR-luminous (L\(_{\rm IR}=3.1\times10^{11}\ \rm L_{\odot}\)). What is particularly interesting about this galaxy is that HST optical/near-infrared images show a remarkably bright and large (1 kpc) clump at one edge of the disk. Our follow-up optical/near-infrared spectroscopy shows Balmer (H\(\alpha\)-H8) and forbidden emission from this clump (OII \(\lambda\)3727, OIII \(\lambda\lambda\)4959,5007, NII \(\lambda\lambda\)6548,6583), indicating that it is a HII region. The HII region appears to have formed in-situ, as kinematically it is part of a rotating disk, and there is no evidence of nearby interacting galaxies. With an extinction correction of A\(_{\rm V}=1.5\) mag, the star formation rate of this giant HII region is \(\sim\)10 M\(_{\odot}\) yr\(^{-1}\), which is exceptionally large, even for high redshift HII regions. Such a large and luminous HII region is often seen at \(z\sim2\) but quite rare in the nearby Universe.
We measure the quasar two-point correlation function over the redshift range 2.2<z<2.8 using data from the Baryon Oscillation Spectroscopic Survey. We use a homogeneous subset of the data consisting ...of 27,129 quasars with spectroscopic redshifts---by far the largest such sample used for clustering measurements at these redshifts to date. The sample covers 3,600 square degrees, corresponding to a comoving volume of 9.7(Gpc/h)^3 assuming a fiducial LambdaCDM cosmology, and it has a median absolute i-band magnitude of -26, k-corrected to z=2. After accounting for redshift errors we find that the redshift space correlation function is fit well by a power-law of slope -2 and amplitude s_0=(9.7\pm 0.5)Mpc/h over the range 3<s<25Mpc/h. The projected correlation function, which integrates out the effects of peculiar velocities and redshift errors, is fit well by a power-law of slope -1 and r_0=(8.4\pm 0.6)Mpc/h over the range 4<R<16Mpc/h. There is no evidence for strong luminosity or redshift dependence to the clustering amplitude, in part because of the limited dynamic range in our sample. Our results are consistent with, but more precise than, previous measurements at similar redshifts. Our measurement of the quasar clustering amplitude implies a bias factor of b~3.5 for our quasar sample. We compare the data to models to constrain the manner in which quasars occupy dark matter halos at z~2.4 and infer that such quasars inhabit halos with a characteristic mass of ~10^{12}Msun/h with a duty cycle for the quasar activity of 1 per cent.
