- ID:
- ivo://CDS.VizieR/J/ApJ/887/38
- Title:
- SDSS RM Project: CIV lags & LCs from 4yrs of data
- Short Name:
- J/ApJ/887/38
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present reverberation-mapping (RM) lags and black hole mass measurements using the CIV{lambda}1549 broad emission line from a sample of 348 quasars monitored as a part of the Sloan Digital Sky Survey RM Project. Our data span four years of spectroscopic and photometric monitoring for a total baseline of 1300 days, allowing us to measure lags up to ~750days in the observed frame (this corresponds to a rest-frame lag of ~300days in a quasar at z=1.5 and ~190days at z=3). We report significant time delays between the continuum and the CIV{lambda}1549 emission line in 48 quasars, with an estimated false-positive detection rate of 10%. Our analysis of marginal lag measurements indicates that there are on the order of ~100 additional lags that should be recoverable by adding more years of data from the program. We use our measurements to calculate black hole masses and fit an updated CIV radius-luminosity relationship. Our results significantly increase the sample of quasars with CIV RM results, with the quasars spanning two orders of magnitude in luminosity toward the high-luminosity end of the CIV radius-luminosity relation. In addition, these quasars are located at some of the highest redshifts (z~1.4-2.8) of quasars with black hole masses measured with RM.
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Search Results
- ID:
- ivo://CDS.VizieR/J/A+A/652/A59
- Title:
- SDSS Solar System Objects
- Short Name:
- J/A+A/652/A59
- Date:
- 22 Feb 2022
- Publisher:
- CDS
- Description:
- The populations of small bodies of the Solar System (asteroids, comets, Kuiper-Belt objects) are used to constrain the origin and evolution of the Solar System. Both their orbital distribution and composition distribution are required to track the dynamical pathway from their regions of formation to their current locations. We aim at increasing the sample of Solar System objects that have multi-filter photometry and compositional taxonomy. We search for moving objects in the archive of the Sloan Digital Sky Survey. We attempt at maximizing the number of detections by using loose constraints on the extraction. We then apply a suite of filters to remove false-positive detections (stars or galaxies) and mark out spurious photometry and astrometry. We release a catalog of 1542522 entries, consisting of 1036322 observations of 379714 known and unique SSOs together with 506200 observations of moving sources not linked with any known SSOs. The catalog completeness is estimated to be about 95% and the purity to be above 95% for known SSOs.
- ID:
- ivo://CDS.VizieR/J/ApJS/166/470
- Title:
- SDSS-Spitzer type I QSOs IR photometry
- Short Name:
- J/ApJS/166/470
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present an analysis of the mid-infrared (MIR) and optical properties of type 1 (broad-line) quasars detected by the Spitzer Space Telescope. The MIR color-redshift relation is characterized to z~3, with predictions to z=7. We demonstrate how combining MIR and optical colors can yield even more efficient selection of active galactic nuclei (AGNs) than MIR or optical colors alone. Composite spectral energy distributions (SEDs) are constructed for 259 quasars with both Sloan Digital Sky Survey and Spitzer photometry, supplemented by near-IR, GALEX, VLA, and ROSAT data, where available.
- ID:
- ivo://CDS.VizieR/J/A+A/561/A33
- Title:
- SDSS star-forming galaxies multi-wavelength study
- Short Name:
- J/A+A/561/A33
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We studied a large sample of ~14000 dwarf star-forming galaxies with strong emission lines. These low-metallicity galaxies with oxygen abundances of 12+logO/H~7.4-8.5 are selected from the Sloan Digital Sky Survey (SDSS) and distributed in the redshift range of z~0-0.6. We modelled spectral energy distributions (SED) of all galaxies, which were based on the SDSS spectra in the visible range of 0.38{mu}m-0.92{mu}m and included both the stellar and ionised gas emission. These SEDs were extrapolated to the UV and mid-infrared ranges to cover the wavelength range of 0.1{mu}m-22{mu}m. The SDSS spectroscopic data were supplemented by photometric data from the GALEX, SDSS, 2MASS, WISE, IRAS, and NVSS all-sky surveys. Using these data, we derived global characteristics of the galaxies, such as their element abundances, luminosities, and stellar masses.
- ID:
- ivo://CDS.VizieR/J/ApJ/884/82
- Title:
- SDSS, WISE and HI data of local spiral galaxies
- Short Name:
- J/ApJ/884/82
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The emerging light from a galaxy is under the influence of its own interstellar medium, as well as its spatial orientation. Considering a sample of 2239 local spiral galaxies in optical (Sloan Digital Sky Survey u, g, r, i, and z) and infrared bands (WISE W1, W1), we study the dependency of the global intrinsic attenuation in spiral galaxies on their morphologies, sizes, and spatial inclinations. Reddening is minimal at the extremes of low mass and gas depletion and maximal in galaxies that are relatively massive and metal-rich and still retain substantial gas reserves. A principal component constructed from observables that monitor galaxy mass, relative H i content to old stars, and infrared surface brightness is strongly correlated with the amplitude of obscuration. We determine both a parametric model for dust obscuration and a nonparametric model based on the Gaussian process formalism. An average dust attenuation curve is derived for wavelengths between 0.36 and 4.5{mu}m.
- ID:
- ivo://CDS.VizieR/J/ApJ/825/126
- Title:
- SEAMBHs. V. The third year
- Short Name:
- J/ApJ/825/126
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This paper reports results of the third-year campaign of monitoring super-Eddington accreting massive black holes (SEAMBHs) in active galactic nuclei (AGNs) between 2014 and 2015. Ten new targets were selected from the quasar sample of the Sloan Digital Sky Survey (SDSS), which have generally been more luminous than the SEAMBH candidates in the last two years. H{beta} lags ({tau}_H{beta}_) in five of the 10 quasars have been successfully measured in this monitoring season. We find that the lags are generally shorter, by large factors, than those of objects with same optical luminosity, in light of the well-known R_H{beta}_-L_5100_ relation. The five quasars have dimensionless accretion rates of dM/dt=10-10^3^. Combining these with measurements of the previous SEAMBHs, we find that the reduction of H{beta} lags depends tightly on accretion rates, {tau}_H{beta}_/{tau}_R-L_{propto}(dM/dt)^-0.42^, where {tau}_R-L_ is the H{beta} lag from the normal R_H{beta}_-L_5100_ relation. Fitting 63 mapped AGNs, we present a new scaling relation for the broad-line region: R_H{beta}_={alpha}_1_l_44_^{beta}1^min [1,(dM/dt)/(dM/dt)_c_)^-{gamma}1^], where l_44_=L_5100_/10^44^erg/s is the 5100{AA} continuum luminosity, and the coefficients are {alpha}_1_=29.6_-2.8_^+2.7^ lt-day, {beta}1=0.56_-0.03_^+0.03^, {gamma}1=0.52_-0.16_^+0.33^, and (dM/dt)_c_=11.19_-6.22_^+2.29^. This relation is applicable to AGNs over a wide range of accretion rates, from 10^-3^ to 10^3^. Implications of this new relation are briefly discussed.
- ID:
- ivo://CDS.VizieR/J/A+A/460/695
- Title:
- Search for Associations Containing Young stars
- Short Name:
- J/A+A/460/695
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report results from a high-resolution optical spectroscopic survey aimed to search for nearby young associations and young stars among optical counterparts of ROSAT All-Sky Survey (<IX/10> and <IX/29>, X-ray sources in the Southern Hemisphere. We selected 1953 late-type (B-V>=0.6), potentially young, optical counterparts out of a total of 9574 1RXS sources for follow-up observations. At least one high-resolution spectrum was obtained for each of 1511 targets. This paper is the first in a series presenting the results of the SACY survey. Here we describe our sample and our observations. We describe a convergence method in the (UVW) velocity space to find associations. As an example, we discuss the validity of this method in the framework of the Beta Pic Association.
- ID:
- ivo://CDS.VizieR/J/ApJ/736/89
- Title:
- Search for companions around nearby massive stars
- Short Name:
- J/ApJ/736/89
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In this study, we present high-contrast imaging of 18 nearby massive stars of which 15 are in the B2-A0 spectral-type range and provide excellent sensitivity to wide companions. By comparing our sensitivities to model predictions of disk instability based on physical criteria for fragmentation and cooling, and using Monte Carlo simulations for orbital distributions, we find that ~85% of such companions should have been detected in our images on average. Given this high degree of completeness, stringent statistical limits can be set from the null-detection result, even with the limited sample size. We find that <30% of massive stars form and retain disk instability planets, brown dwarfs, and very low mass stars of <100M_jup_ within 300AU, at 99% confidence. These results, combined with previous findings in the literature, lead to the conclusion that core accretion is likely the dominant mode of planet formation.
- ID:
- ivo://CDS.VizieR/J/A+A/509/A52
- Title:
- Search for companions with VLT/NACO
- Short Name:
- J/A+A/509/A52
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Since November 2002, we have conducted the largest deep imaging survey of the young, nearby associations of the southern hemisphere. Our goal is detection and characterization of substellar companions at intermediate (10-500AU) physical separations. We have observed a sample of 88 stars, mostly G to M dwarfs, that we essentially identify as younger than 100Myr and closer to Earth than 100pc. The VLT/NACO adaptive optics instrument of the ESO Paranal Observatory was used to explore the faint circumstellar environment between typically 0.1 and 10". We report the discovery of 17 new close (0.1-5.0") multiple systems. HIP 108195AB and C (F1III-M6), HIP 84642AB (a~14AU, K0-M5) and TWA 22AB (a~1.8AU; M6-M6) confirmed comoving systems. TWA 22AB is likely to be a astrometric calibrator that can be used to test evolutionary predictions. Among our complete sample, a total of 65 targets observed with deep coronagraphic imaging. About 240 faint candidates were detected around 36 stars. Follow-up observations VLT or HST for 83% of these stars enabled us to identify a fraction of contaminants. The latest results about the substellar companions to GSC 08047-00232, AB Pic and 2M1207, confirmed during this survey and published earlier, are reviewed. Finally, the statistical analysis of our complete set of coronagraphic limits enables us to place constraints on the physical and properties of giant planets between typically 20 and 150AU.
- ID:
- ivo://CDS.VizieR/J/ApJ/700/1647
- Title:
- Search for planetary companions with Spitzer/IRAC
- Short Name:
- J/ApJ/700/1647
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Fomalhaut and {epsilon} Eridani are two young, nearby stars that possess extended debris disks whose structures suggest the presence of perturbing planetary objects. With its high sensitivity and stable point-spread function, Spitzer/Infrared Array Camera (IRAC) is uniquely capable of detecting cool, Jupiter-like planetary companions whose peak emission is predicted to occur near 4.5um. We report on deep IRAC imaging of these two stars, taken at 3.6 and 4.5um using subarray mode and in all four channels in wider-field full array mode. Observations acquired at two different telescope roll angles allowed faint surrounding objects to be separated from the stellar diffraction pattern. No companion candidates were detected at the reported position of Fomalhaut b with 3{sigma} model-dependent mass upper limits of 3M_J_ (for an age of 200Myr). Around {epsilon} Eridani, we instead set a limit of 4 and <~1M_J_ (1Gyr model age) at the inner and outer edge of the submillimeter debris ring, respectively. These results are consistent with non-detections in recent near-infrared imaging searches, and set the strongest limits to date on the presence of planets outside {epsilon} Eridani submillimeter ring.
