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891. Spectroscopy of PC 1643+4631A,B
ID:
ivo://CDS.VizieR/J/AJ/136/181
Title:
Spectroscopy of PC 1643+4631A,B
Short Name:
J/AJ/136/181
Date:
21 Oct 2021
Publisher:
CDS
Description:
This is the first measurement and detection of coherence in the intergalactic medium (IGM) at substantially high redshift (z~3.8) and on large physical scales (~2.5h^-1^_70_Mpc). We perform the measurement by presenting new observations of the high-redshift quasar pair PC 1643+4631A, B and their Ly{alpha}-absorber coincidences. With data collected from Keck I Low Resolution Imaging Spectrometer (LRIS) in a 10200s integration, we have full coverage of the Ly{alpha} forest over the redshift range 2.6<z<3.8 at a resolution of 3.6{AA} (~220km/s).
892. Spectroscopy of QSO pairs
ID:
ivo://CDS.VizieR/J/ApJS/175/29
Title:
Spectroscopy of QSO pairs
Short Name:
J/ApJS/175/29
Date:
21 Oct 2021
Publisher:
CDS
Description:
The Ly{alpha} forest has opened a new redshift regime for cosmological investigation. At z>2 it provides a unique probe of cosmic geometry and an independent constraint on dark energy that is not subject to standard candle or ruler assumptions. In Paper I of this series on using the Ly{alpha} forest observed in pairs of QSOs for a new application of the Alcock-Paczynski test, we present and discuss the results of a campaign to obtain moderate-resolution spectroscopy (FWHM~2.5{AA}) of the Ly{alpha} forest in pairs of QSOs with small redshift differences ({Delta}z<0.25, z>2.2) and arcminute separations ({Theta}<5'). This data set, composed of seven individual QSOs, 35 pairs, and one triplet, is also well suited for future investigations of the coherence of Ly{alpha} absorbers on ~1Mpc transverse scales and the transverse proximity effect. We note seven revisions for previously published QSO identifications and/or redshifts.
893. Spectroscopy of quasar binary candidates
ID:
ivo://CDS.VizieR/J/ApJ/678/635
Title:
Spectroscopy of quasar binary candidates
Short Name:
J/ApJ/678/635
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present spectroscopy of binary quasar candidates, with component separations of 3"<={Delta}{theta}<6", selected from SDSS DR4 using kernel density estimation (KDE). Of our 27 new quasar pair observations, 10 are binary quasars, which doubles the number of known g<21 binaries with 3"<={Delta}{theta}<6" separations. Several of our observed binaries are wide-separation lens candidates that merit additional higher resolution spectroscopy, as well as deep imaging to search for lensing galaxies. Our candidates are initially selected by UV excess (u-g<1), but are otherwise selected irrespective of the relative colors of the quasar pair, and we thus use them to suggest optimal color similarity and photometric redshift approaches for targeting binary quasars or projected quasar pairs. We find that a third or more of all binary quasars have quite dissimilar components on the basis of a typical color similarity criterion ({chi}^2^_color_<~20). From a sample that is complete on proper scales of 23.7h^-1^kpc<R_prop_<29.9h^-1^kpc, we determine the projected quasar correlation function.
894. Spectroscopy of 88 z<0.7 SDSS QSOs
ID:
ivo://CDS.VizieR/J/ApJS/201/23
Title:
Spectroscopy of 88 z<0.7 SDSS QSOs
Short Name:
J/ApJS/201/23
Date:
21 Oct 2021
Publisher:
CDS
Description:
We have carried out a systematic search for subparsec supermassive black hole (BH) binaries among z<~0.7 Sloan Digital Sky Survey quasars. These are predicted by models of supermassive BH and host galaxy coevolution, therefore their census and population properties constitute an important test of these models. In our working hypothesis, one of the two BHs accretes at a much higher rate than the other and carries with it the only broad emission line region of the system, making the system analogous to a single-lined spectroscopic binary star. Accordingly, we used spectroscopic principal component analysis to search for broad H{beta} emission lines that are displaced from the quasar rest frame by |{Delta}{nu}|>~1000km/s. This method also yields candidates for rapidly recoiling BHs. Of the 88 candidates, several were previously reported in the literature. We found a correlation between the peak offset and skewness of the broad H{beta} profiles, suggesting a common physical explanation for these profiles. We carried out follow-up spectroscopic observations of 68 objects to search for changes in the peak velocities of the H{beta} lines.
895. Spectroscopy & V-band monitoring of CTS C30.10
ID:
ivo://CDS.VizieR/J/ApJ/880/46
Title:
Spectroscopy & V-band monitoring of CTS C30.10
Short Name:
J/ApJ/880/46
Date:
21 Oct 2021
Publisher:
CDS
Description:
We report 6yr monitoring of distant bright quasar CTS C30.10 (z=0.90052) with the Southern African Large Telescope. We measured the rest-frame time lag of 562_-68_^+116^ days between the continuum variations and the response of the MgII emission line, using six different methods. This time delay, combined with other available measurements of MgII line delay, mostly for lower-redshift sources, shows that the MgII line reverberation implies a radius-luminosity relation very similar to the one based on a more frequently studied H{beta} line.
896. Spectrum of QSO XMMC 2028
ID:
ivo://CDS.VizieR/J/A+A/578/A11
Title:
Spectrum of QSO XMMC 2028
Short Name:
J/A+A/578/A11
Date:
21 Oct 2021
Publisher:
CDS
Description:
Gas outflows are believed to play a pivotal role in shaping galaxies, as they regulate both star formation and black hole growth. Despite their ubiquitous presence, the origin and the acceleration mechanism of such powerful and extended winds is not yet understood. Direct observations of the cold gas component in objects with detected outflows at other wavelengths are needed to assess the impact of the outflow on the host galaxy interstellar medium (ISM). We observed with the Plateau de Bure Interferometer an obscured quasar at z Gas outflows are believed to play a pivotal role in shaping galaxies, as they regulate both star formation and black hole growth. Despite their ubiquitous presence, the origin and the acceleration mechanism of such powerful and extended winds is not yet understood. Direct observations of the cold gas component in objects with detected outflows at other wavelengths are needed to assess the impact of the outflow on the host galaxy interstellar medium (ISM). We observed with the Plateau de Bure Interferometer an obscured quasar at z~1.5, XID2028, for which the presence of an ionised outflow has been unambiguously signalled by NIR spectroscopy. The detection of ^12^CO(3-2) emission in this source allows us to infer the molecular gas content and compare it to the ISM mass derived from the dust emission. We then analyze the results in the context of recent insights on scaling relations, which describe the gas content of the overall population of star-forming galaxies at a similar redshifts.
897. SpIES: the Spitzer IRAC Equatorial Survey
ID:
ivo://CDS.VizieR/J/ApJS/225/1
Title:
SpIES: the Spitzer IRAC Equatorial Survey
Short Name:
J/ApJS/225/1
Date:
21 Oct 2021
Publisher:
CDS
Description:
We describe the first data release from the Spitzer-IRAC Equatorial Survey (SpIES); a large-area survey of ~115deg^2^ in the Equatorial SDSS Stripe 82 field using Spitzer during its "warm" mission phase. SpIES was designed to probe sufficient volume to perform measurements of quasar clustering and the luminosity function at z>=3 to test various models for "feedback" from active galactic nuclei (AGNs). Additionally, the wide range of available multi-wavelength, multi-epoch ancillary data enables SpIES to identify both high-redshift (z>=5) quasars as well as obscured quasars missed by optical surveys. SpIES achieves 5{sigma} depths of 6.13uJy (21.93 AB magnitude) and 5.75uJy (22.0 AB magnitude) at 3.6 and 4.5um, respectively --depths significantly fainter than the Wide-field Infrared Survey Explorer (WISE). We show that the SpIES survey recovers a much larger fraction of spectroscopically confirmed quasars (~98%) in Stripe 82 than are recovered by WISE (~55%). This depth is especially powerful at high-redshift (z>=3.5), where SpIES recovers 94% of confirmed quasars, whereas WISE only recovers 25%. Here we define the SpIES survey parameters and describe the image processing, source extraction, and catalog production methods used to analyze the SpIES data. In addition to this survey paper, we release 234 images created by the SpIES team and three detection catalogs: a 3.6um only detection catalog containing ~6.1 million sources, a 4.5um only detection catalog containing ~6.5 million sources, and a dual-band detection catalog containing ~5.4 million sources.
898. Spitzer/IRAC variability survey of Bootes field
ID:
ivo://CDS.VizieR/J/ApJ/817/119
Title:
Spitzer/IRAC variability survey of Bootes field
Short Name:
J/ApJ/817/119
Date:
21 Oct 2021
Publisher:
CDS
Description:
The Decadal IRAC Bootes Survey is a mid-IR variability survey of the ~9deg^2^ of the NDWFS Bootes Field and extends the time baseline of its predecessor, the Spitzer Deep, Wide-Field Survey (SDWFS), from 4 to 10 years. The Spitzer Space Telescope visited the field five times between 2004 and 2014 at 3.6 and 4.5{mu}m. We provide the difference image analysis photometry for a half a million mostly extragalactic sources. In mid-IR color-color plane, sources with quasar colors constitute the largest variability class (75%), 16% of the variable objects have stellar colors and the remaining 9% have the colors of galaxies. Adding the fifth epoch doubles the number of variable active galactic nuclei (AGNs) for the same false positive rates as in SDWFS, or increases the number of sources by 20% while decreasing the false positive rates by factors of 2-3 for the same variability amplitude. We quantify the ensemble mid-IR variability of ~1500 spectroscopically confirmed AGNs using single power-law structure functions (SFs), which we find to be steeper (index {gamma}~0.45) than in the optical ({gamma}~0.3), leading to much lower amplitudes at short time-lags. This provides evidence for large emission regions, smoothing out any fast UV/optical variations, as the origin of infrared quasar variability. The mid-IR AGN SF slope {gamma} seems to be uncorrelated with both the luminosity and rest-frame wavelength, while the amplitude shows an anti-correlation with the luminosity and a correlation with the rest-frame wavelength.
899. Spitzer/IRS ATLAS project source
ID:
ivo://CDS.VizieR/J/MNRAS/414/500
Title:
Spitzer/IRS ATLAS project source
Short Name:
J/MNRAS/414/500
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present a panoramic atlas of Spitzer/Infrared Spectrograph (IRS) spectra of extragalactic sources collected from the recent literature, with value-added measurements of their spectral features obtained in a homogeneous and concise manner. The atlas covers the full spectrum of the extragalactic Universe and includes star-forming galaxies, obscured and unobscured active galaxies, luminous and ultra-luminous infrared galaxies, and hybrid objects. Measured features such as the polycyclic aromatic hydrocarbons, the strength of the silicates in emission or absorption around 9.7um, rest-frame monochromatic luminosities or colours, combined with measurements derived from spectral decomposition are used to establish diagnostics that allow for classification of sources, based on their infrared properties alone. Average templates of the various classes are also derived. The full atlas with the value-added measurements and ancillary archival data are publicly available at http://www.denebola.org/atlas, with full references to the original data.
900. Spitzer observations of radio-loud AGNs (CARLA)
ID:
ivo://CDS.VizieR/J/ApJ/769/79
Title:
Spitzer observations of radio-loud AGNs (CARLA)
Short Name:
J/ApJ/769/79
Date:
21 Oct 2021
Publisher:
CDS
Description:
We report the first results from the Clusters Around Radio-Loud AGN program, a Cycle 7 and 8 Spitzer Space Telescope snapshot program to investigate the environments of a large sample of obscured and unobscured luminous radio-loud active galactic nuclei (AGNs) at 1.2<z<3.2. These data, obtained for 387 fields, reach 3.6 and 4.5{mu}m depths of [3.6]_AB_=22.6 and [4.5]_AB_=22.9 at the 95% completeness level, which is two to three times fainter than L* in this redshift range. By using the color cut [3.6]-[4.5]>-0.1 (AB), which efficiently selects high-redshift (z>1.3) galaxies of all types, we identify galaxy cluster member candidates in the fields of the radio-loud AGN. The local density of these Infrared Array Camera (IRAC)-selected sources is compared to the density of similarly selected sources in blank fields. We find that 92% of the radio-loud AGN reside in environments richer than average. The majority (55%) of the radio-loud AGN fields are found to be overdense at a>=2{sigma} level; 10% are overdense at a>=5{sigma} level. A clear rise in surface density of IRAC-selected sources toward the position of the radio-loud AGN strongly supports an association of the majority of the IRAC-selected sources with the radio-loud AGN. Our results provide solid statistical evidence that radio-loud AGN are likely beacons for finding high-redshift galaxy (proto-)clusters. We investigate how environment depends on AGN type (unobscured radio-loud quasars versus obscured radio galaxies), radio luminosity and redshift, finding no correlation with either AGN type or radio luminosity. We find a decrease in density with redshift, consistent with galaxy evolution for this uniform, flux-limited survey. These results are consistent with expectations from the orientation-driven AGN unification model, at least for the high radio luminosity regimes considered in this sample.