- ID:
- ivo://CDS.VizieR/J/ApJ/768/13
- Title:
- FIR properties of SDSS type 1 quasars
- Short Name:
- J/ApJ/768/13
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We use the Spitzer Space Telescope Enhanced Imaging Products and the Spitzer Archival Far-InfraRed Extragalactic Survey to study the spectral energy distributions (SEDs) of spectroscopically confirmed type 1 quasars selected from the Sloan Digital Sky Survey (SDSS). By combining the Spitzer and SDSS data with the Two Micron All Sky Survey, we are able to construct a statistically robust rest-frame 0.1-100{mu}m type 1 quasar template. We find that the quasar population is well-described by a single power-law SED at wavelengths less than 20{mu}m, in good agreement with previous work. However, at longer wavelengths, we find a significant excess in infrared luminosity above an extrapolated power-law, along with significant object-to-object dispersion in the SED. The mean excess reaches a maximum of 0.8dex at rest-frame wavelengths near 100{mu}m.
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Search Results
- ID:
- ivo://CDS.VizieR/J/ApJ/811/58
- Title:
- FIR properties of SDSS 0.1<z<5 quasars
- Short Name:
- J/ApJ/811/58
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Using the public data from the Herschel wide-field surveys, we study the far-infrared properties of optical-selected quasars from the Sloan Digital Sky Survey. Within the common area of ~172deg^2^, we have identified the far-infrared counterparts for 354 quasars, among which 134 are highly secure detections in the Herschel 250um band (signal-to-noise ratios >=5). This sample is the largest far-infrared quasar sample of its kind, and spans a wide redshift range of 0.14<=z<=4.7. Their far-infrared spectral energy distributions, which are due to the cold-dust components within the host galaxies, are consistent with being heated by active star formation. In most cases (>~80%), their total infrared luminosities as inferred from only their far-infrared emissions (L_IR_^(cd)^) already exceed 10^12^L_{sun}_, and thus these objects qualify as ultra-luminous infrared galaxies. There is no correlation between L_IR_^(cd)^ and the absolute magnitudes, the black hole masses or the X-ray luminosities of the quasars, which further support that their far-infrared emissions are not due to their active galactic nuclei. A large fraction of these objects (>~50%-60%) have star-formation rates >~300M_{sun}_/yr. Such extreme starbursts among optical quasars, however, is only a few percent. This fraction varies with redshift, and peaks at around z~2. Among the entire sample, 136 objects have secure estimates of their cold-dust temperatures (T), and we find that there is a dramatic increasing trend of T with increasing L_IR_^(cd)^. We interpret this trend as the envelope of the general distribution of infrared galaxies on the (T, L_IR_^(cd)^) plane.
- ID:
- ivo://CDS.VizieR/J/MNRAS/489/2030
- Title:
- First Byurakan Survey of Late-Type Stars - v2
- Short Name:
- J/MNRAS/489/2030
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A total of 18 lists of the First Byurakan Survey of Late-Type Stars (FBS LTS) were published between 1990 and 2016. The stars were found on FBS low-dispersion spectroscopic plates. A systematic search and selection were carried out on a surface of ~16000deg^2^ on almost the whole area of the FBS. As a result, the "Revised and Updated Catalogue of the First Byurakan Survey of Late-Type Stars" was generated (FBS LTS v1; see Cat. III/266 -- 1045 objects). We present the second version of the catalogue of FBS LTS with new data (FBS LTS v2), comprising 1471 objects. It is a homogeneous and complete data base for high-Galactic-latitude, late-type stars, including M and C types. Since 2007, all FBS low-resolution spectral plates have been digitized. All digitized FBS (DFBS) spectral plates have been analysed with FITSVIEW and SAO IMAGE DS9, and numerous relatively faint LTSs have been discovered. We have performed cross-correlations with DFBS, USNO-B1.0, 2MASS, AllWISE, IRAS PSC/FSC, AKARI, ROSAT BSC/FSC, GCVS, SDSS and added updated SIMBAD data. For numerous new detected objects, we present accurate DSS2 positions, approximate spectral subtypes refined from the DFBS low-dispersion spectra, luminosity classes estimated from 2MASS colours, and available proper motions for 1471 FBS LTSs. The Revised and Updated Catalogue v2 lists a large number of completely new objects, which promises to extend very significantly the census of M giants, faint N-type asymptotic giant branch carbon stars, CH-type carbon giants at high Galactic latitudes, and M dwarfs in the Solar vicinity up to 16.0-17.0mag in the visual. Some important data from Gaia DR2 and supplementary spectra from the Byurakan Astrophysical Observatory 2.6m and LAMOST telescopes are presented.
- ID:
- ivo://CDS.VizieR/J/A+A/601/A81
- Title:
- FIRST catalog of FR II radio galaxies
- Short Name:
- J/A+A/601/A81
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We built a catalog of 122 FR II radio galaxies, called FRIICAT, selected from a published sample obtained by combining observations from the NVSS, FIRST, and SDSS surveys. The catalog includes sources with redshift <=0.15, an edge-brightened radio morphology, and those with at least one of the emission peaks located at radius r larger than 30 kpc from the center of the host. The radio luminosity at 1.4GHz of the FRIICAT sources covers the range L1.4~10^39.5^-10^42.5^erg/s. The FRIICAT catalog has 90% of low and 10% of high excitation galaxies (LEGs and HEGs), respectively. The properties of these two classes are significantly different. The FRIICAT LEGs are mostly luminous (-20>~Mr>~-24), red early-type galaxies with black hole masses in the range 10^8^<~M_BH_<~10^9^M_{sun}_; they are essentially indistinguishable from the FR Is belonging to the FRICAT. The HEG FR IIs are associated with optically bluer and mid-IR redder hosts than the LEG FR IIs and to galaxies and black holes that are smaller, on average, by a factor ~2. FR IIs have a factor ~3higher average radio luminosity than FR Is. Nonetheless, most (~90%) of the selected FR IIs have a radio power that is lower, by as much as a factor of ~100, than the transition value between FR Is and FR IIs found in the 3C sample. The correspondence between the morphological classification of FR I and FR II and the separation in radio power disappears when including sources selected at low radio flux thresholds, which is in line with previous results. In conclusion, a radio source produced by a low power jet can be edge brightened or edge darkened, and the outcome is not related to differences in the optical properties of the host galaxy.
- ID:
- ivo://CDS.VizieR/J/AJ/133/2097
- Title:
- FIRST "Winged" and X-shaped radio source candidates
- Short Name:
- J/AJ/133/2097
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A small number of double-lobed radio galaxies (17 from our own census of the literature) show an additional pair of low surface brightness "wings," thus forming an overall X-shaped appearance. Using the VLA FIRST survey database, we are compiling a large sample of winged and X-shaped radio sources for such studies. As a first step toward this goal, an initial sample of 100 new candidate objects of this type are presented in this paper.
- ID:
- ivo://CDS.VizieR/J/ApJ/724/866
- Title:
- Follow-up observations of HAT-P-15
- Short Name:
- J/ApJ/724/866
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the discovery of HAT-P-15b, a transiting extrasolar planet in the "period valley," a relatively sparsely populated period regime of the known extrasolar planets. The host star, GSC 2883-01687, is a G5 dwarf with V=12.16. It has a mass of 1.01+/-0.04M_{sun}_, radius of 1.08+/-0.04R_{sun}_, effective temperature 5568+/-90K, and metallicity [Fe/H]=+0.22+/-0.08. The planetary companion orbits the star with a period P=10.863502+/-0.000027 days, transit epoch T_c_=2454638.56019+/-0.00048(BJD), and transit duration 0.2285+/-0.0015days. It has a mass of 1.946+/-0.066M_J_ and radius of 1.072+/-0.043R_J_ yielding a mean density of 1.96+/-0.22g/cm^3^. At an age of 6.8^+2.5^_-1.6_Gyr, the planet is H/He-dominated and theoretical models require about 2% (10M_{earth}_) worth of heavy elements to reproduce its measured radius. With an estimated equilibrium temperature of ~820K during transit, and ~1000K at occultation, HAT-P-15b is a potential candidate to study moderately cool planetary atmospheres by transmission and occultation spectroscopy.
- ID:
- ivo://CDS.VizieR/J/ApJ/887/126
- Title:
- Follow-up obs. of the PSJ0147+4630 lens system
- Short Name:
- J/ApJ/887/126
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Because follow-up observations of quadruple gravitational lens systems are of extraordinary importance for astrophysics and cosmology, we present single-epoch optical spectra and r-band light curves of PS J0147+4630. This recently discovered system mainly consists of four images ABCD of a background quasar around a foreground galaxy G that acts as a gravitational lens. First, we use long-slit spectroscopic data in the Gemini Observatory Archive and a multi-component fitting to accurately resolve the spectra of A, D, and G. The spectral profile of G resembles that of an early-type galaxy at a redshift of 0.678+/-0.001, which is about 20% higher than the previous estimate. Additionally, the stellar velocity dispersion is measured to ~5% precision. Second, our early r-band monitoring with the Liverpool Telescope leads to accurate light curves of the four quasar images. Adopting time delays predicted by the lens model, the new lens redshift, and a standard cosmology, we report the detection of microlensing variations in C and D as large as ~0.1mag on timescales of a few hundred days. We also estimate an actual delay between A and B of a few days (B is leading), which demonstrates the big potential of optical monitoring campaigns of PS J0147+4630.
- ID:
- ivo://CDS.VizieR/J/ApJ/734/109
- Title:
- Follow-up photometry of HAT-P-27
- Short Name:
- J/ApJ/734/109
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the discovery of HAT-P-27b, an exoplanet transiting the moderately bright G8 dwarf star GSC 0333-00351 (V=12.214). The orbital period is 3.039586+/-0.000012 days, the reference epoch of transit is 2455186.01879+/-0.00054 (BJD), and the transit duration is 0.0705+/-0.0019 days. The host star with its effective temperature 5300+/-90K is somewhat cooler than the Sun and is more metal-rich with a metallicity of +0.29+/-0.10. Its mass is 0.94+/-0.04M_{sun}_ and radius is 0.90^+0.05^_-0.04_R_{sun}_. For the planetary companion we determine a mass of 0.660+/-0.033M_J_ and radius of 1.038^+0.077^_-0.058_R_J_. For the 30 known transiting exoplanets between 0.3M_J_ and 0.8M_J_, a negative correlation between host star metallicity and planetary radius and an additional dependence of planetary radius on equilibrium temperature are confirmed at a high level of statistical significance.
- ID:
- ivo://CDS.VizieR/J/ApJ/834/107
- Title:
- Follow-up photometry of M101 OT2015-1
- Short Name:
- J/ApJ/834/107
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of optical, near-infrared, and mid-infrared observations of M101 OT2015-1 (PSN J14021678+5426205), a luminous red transient in the Pinwheel galaxy (M101), spanning a total of 16 years. The light curve showed two distinct peaks with absolute magnitudes M_r_<=-12.4 and M_r_~-12, on 2014 November 11 and 2015 February 17, respectively. The spectral energy distributions during the second maximum show a cool outburst temperature of ~3700K and low expansion velocities (~-300km/s) for the HI, CaII, BaII, and KI lines. From archival data spanning 15-8 years before the outburst, we find a single source consistent with the optically discovered transient, which we attribute to being the progenitor; it has properties consistent with being an F-type yellow supergiant with L~8.7x10^4^L_{sun}_, T_eff_~7000K, and an estimated mass of M1=18+/-1M_{sun}_. This star has likely just finished the H-burning phase in the core, started expanding, and is now crossing the Hertzsprung gap. Based on the combination of observed properties, we argue that the progenitor is a binary system, with the more evolved system overfilling the Roche lobe. Comparison with binary evolution models suggests that the outburst was an extremely rare phenomenon, likely associated with the ejection of the common envelope of a massive star. The initial mass of the primary fills the gap between the merger candidates V838 Mon (5-10M_{sun}_) and NGC 4490-OT (30M_{sun}_).
- ID:
- ivo://CDS.VizieR/J/ApJ/874/8
- Title:
- Follow-up spectroscopy of SDSS changing-look QSOs
- Short Name:
- J/ApJ/874/8
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Active galactic nuclei (AGNs) that show strong rest-frame optical/UV variability in their blue continuum and broad line emission are classified as changing-look AGN, or at higher luminosities, changing-look quasars (CLQs). These surprisingly large and sometimes rapid transitions challenge accepted models of quasar physics and duty cycles, offer several new avenues for study of quasar host galaxies, and open a wider interpretation of the cause of differences between broad and narrow-line AGN. To better characterize extreme quasar variability, we present follow-up spectroscopy as part of a comprehensive search for CLQs across the full Sloan Digital Sky Survey (SDSS) footprint using spectroscopically confirmed quasars from the SDSS DR7 catalog. Our primary selection requires large-amplitude (|{Delta}g|>1mag, |{Delta}r|>0.5mag) variability over any of the available time baselines probed by the SDSS and Pan-STARRS 1 surveys. We employ photometry from the Catalina Sky Survey to verify variability behavior in CLQ candidates where available, and confirm CLQs using optical spectroscopy from the William Herschel, MMT, Magellan, and Palomar telescopes. For our adopted signal-to-noise ratio threshold on variability of broad H{beta} emission, we find 17 new CLQs, yielding a confirmation rate of >~20%. These candidates are at lower Eddington ratio relative to the overall quasar population, which supports a disk-wind model for the broad line region. Based on our sample, the CLQ fraction increases from 10% to roughly half as the continuum flux ratio between repeat spectra at 3420{AA} increases from 1.5 to 6. We release a catalog of more than 200 highly variable candidates to facilitate future CLQ searches.
