- ID:
- ivo://CDS.VizieR/J/A+A/609/A106
- Title:
- PTF11mnb Bgri light curves
- Short Name:
- J/A+A/609/A106
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We study PTF11mnb, a He-poor supernova (SN) whose light curves resemble those of SN 2005bf, a peculiar double-peaked stripped-envelope (SE) SN, until the declining phase after the main peak. We investigate the mechanism powering its light curve and the nature of its progenitor star. Optical photometry and spectroscopy of PTF11mnb are presented. We compared light curves, colors and spectral properties to those of SN 2005bf and normal SE SNe. We built a bolometric light curve and modeled this light curve with the SuperNova Explosion Code (SNEC) hydrodynamical code explosion of a MESA progenitor star and semi-analytic models.
Number of results to display per page
Search Results
- ID:
- ivo://CDS.VizieR/J/A+A/593/A68
- Title:
- PTF12os and iPTF13bvn spectra and light curves
- Short Name:
- J/A+A/593/A68
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We investigate two stripped-envelope supernovae (SNe) discovered in the nearby galaxy NGC 5806 by the (i)PTF. We classify PTF12os as a Type IIb SN based on our spectral sequence; iPTF13bvn has previously been classified as Type Ib. Our main objective is to constrain the explosion parameters of iPTF12os and iPTF13bvn, and to put constraints on the SN progenitors, using our comprehensive photometric and spectroscopic datasets.
- ID:
- ivo://CDS.VizieR/J/ApJS/232/23
- Title:
- 27 pulsating DA WDs follow-up observations
- Short Name:
- J/ApJS/232/23
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present photometry and spectroscopy for 27 pulsating hydrogen-atmosphere white dwarfs (DAVs; a.k.a. ZZ Ceti stars) observed by the Kepler space telescope up to K2 Campaign 8, an extensive compilation of observations with unprecedented duration (>75 days) and duty cycle (>90%). The space-based photometry reveals pulsation properties previously inaccessible to ground- based observations. We observe a sharp dichotomy in oscillation mode line widths at roughly 800s, such that white dwarf pulsations with periods exceeding 800s have substantially broader mode line widths, more reminiscent of a damped harmonic oscillator than a heat-driven pulsator. Extended Kepler coverage also permits extensive mode identification: we identify the spherical degree of 87 out of 201 unique radial orders, providing direct constraints of the rotation period for 20 of these 27 DAVs, more than doubling the number of white dwarfs with rotation periods determined via asteroseismology. We also obtain spectroscopy from 4m-class telescopes for all DAVs with Kepler photometry. Using these homogeneously analyzed spectra, we estimate the overall mass of all 27 DAVs, which allows us to measure white dwarf rotation as a function of mass, constraining the endpoints of angular momentum in low- and intermediate-mass stars. We find that 0.51-0.73M{sun} white dwarfs, which evolved from 1.7-3.0M{sun} ZAMS progenitors, have a mean rotation period of 35hr with a standard deviation of 28hr, with notable exceptions for higher-mass white dwarfs.
- ID:
- ivo://CDS.VizieR/J/MNRAS/396/223
- Title:
- QSO candidates selection in VO era
- Short Name:
- J/MNRAS/396/223
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a method for the photometric selection of candidate quasars in multiband surveys. The method makes use of a priori knowledge derived from a subsample of spectroscopic confirmed quasi-stellar objects (QSOs) to map the parameter space. The disentanglement of QSOs candidates and stars is performed in the colour space through the combined use of two algorithms, the probabilistic principal surfaces and the negative entropy clustering, which are for the first time used in an astronomical context. Both methods have been implemented in the voneural package on the Astrogrid Virtual Observatory platform. Even though they belong to the class of the unsupervised clustering tools, the performances of the method are optimized by using the available sample of confirmed quasars and it is therefore possible to learn from any improvement in the available 'base of knowledge'. The method has been applied and tested on both optical and optical plus near-infrared data extracted from the visible Sloan Digital Sky Survey (SDSS) and infrared United Kingdom Infrared Deep Sky Survey-Large Area Survey public data bases. In all cases, the experiments lead to high values of both efficiency and completeness, comparable if not better than the methods already known in the literature. A catalogue of optical candidate QSOs extracted from the SDSS Data Release 7 Legacy photometric data set has been produced.
- ID:
- ivo://CDS.VizieR/J/MNRAS/447/3856
- Title:
- QSO-galaxy pairs from SDSS
- Short Name:
- J/MNRAS/447/3856
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present photometric and spectroscopic measurements of 53 QSO-galaxy pairs from the Sloan Digital Sky Survey (SDSS), where nebular emission lines from a 0<z<0.84 foreground galaxy are detected in the fibre spectra of a background QSO, bringing the overall sample to 103 QSO-galaxy pairs detected in the SDSS. We here study the nature of these systems. Detected foreground galaxies appear at impact parameters between 0.37 and 12.68 kpc. The presence of oxygen and Balmer emission lines allows us to determine the emission line metallicities for our sample, which are on average supersolar in value. Star formation rates for our sample are in the range 0.01-12M_{sun}_/yr. We utilize photometric redshift fitting techniques to estimate the M* values of our galaxies (logM*=7.34-11.54), and extrapolate this relationship to those galaxies with no imaging detections. Where available, we measure the absorption features present in the QSO spectrum due to the foreground galaxy and the relationships between their rest equivalent widths. We report an anticorrelation between impact parameter and E(B-V)(g-i), as well as a correlation between galaxy colour (u- r) and E(B-V)(g-i). We find that our sample is one of late-type, star-forming galaxies comparable to field galaxies in a similar redshift range, providing important clues to better understand absorption systems. These galaxies represent a sample of typical galaxies in the local Universe for which abundances, extinction, morphology, and absorption properties may be measured using background QSOs with great potential for follow-up observations.
- ID:
- ivo://CDS.VizieR/J/ApJS/194/45
- Title:
- QSO properties from SDSS-DR7
- Short Name:
- J/ApJS/194/45
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a compilation of properties of the 105783 quasars in the Sloan Digital Sky Survey Data Release 7 (DR7) quasar catalog (Cat. VII/260). In this product, we compile continuum and emission line measurements around the H{alpha}, H{beta}, MgII, and CIV regions, as well as other quantities such as radio properties, and flags indicating broad absorption line quasars, disk emitters, etc. We also compile virial black hole mass estimates based on various calibrations. For the fiducial virial mass estimates we use the Vestergaard & Peterson (VP06; 2006ApJ...641..689V) calibrations for H{beta} and CIV, and our own calibration for MgII which matches the VP06 H{beta} masses on average. We describe the construction of this catalog and discuss its limitations.
- ID:
- ivo://CDS.VizieR/J/ApJ/728/26
- Title:
- QSO selection based on photometric variability
- Short Name:
- J/ApJ/728/26
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We develop a method for separating quasars from other variable point sources using Sloan Digital Sky Survey (SDSS) Stripe 82 light-curve data for ~10000 variable objects. To statistically describe quasar variability, we use a damped random walk (DRW) model parametrized by a damping timescale, {tau}, and an asymptotic amplitude (structure function), SF_{infinite}_. With the aid of an SDSS spectroscopically confirmed quasar sample, we demonstrate that variability selection in typical extragalactic fields with low stellar density can deliver complete samples with reasonable purity (or efficiency, E). Compared to a selection method based solely on the slope of the structure function, the inclusion of the {tau} information boosts E from 60% to 75% while maintaining a highly complete sample (98%) even in the absence of color information. For a completeness of C=90%, E is boosted from 80% to 85%. Conversely, C improves from 90% to 97% while maintaining E=80% when imposing a lower limit on {tau}. With the aid of color selection, the purity can be further boosted to 96%, with C=93%. Hence, selection methods based on variability will play an important role in the selection of quasars with data provided by upcoming large sky surveys, such as Pan-STARRS and the Large Synoptic Survey Telescope (LSST). In summary, given an adequate survey cadence, photometric variability provides an even better method than color selection for separating quasars from stars.
- ID:
- ivo://CDS.VizieR/J/ApJS/219/39
- Title:
- QSOs selection from SDSS and WISE
- Short Name:
- J/ApJS/219/39
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We identify 885503 type 1 quasar candidates to i<~22 using the combination of optical and mid-IR photometry. Optical photometry is taken from the Sloan Digital Sky Survey-III: Baryon Oscillation Spectroscopic Survey (SDSS-III/BOSS), while mid-IR photometry comes from a combination of data from the Wide-field Infrared Survey Explorer (WISE) "AllWISE" data release and several large-area Spitzer Space Telescope fields. Selection is based on a Bayesian kernel density algorithm with a training sample of 157701 spectroscopically confirmed type 1 quasars with both optical and mid-IR data. Of the quasar candidates, 733713 lack spectroscopic confirmation (and 305623 are objects that we have not previously classified as photometric quasar candidates). These candidates include 7874 objects targeted as high-probability potential quasars with 3.5<z<5 (of which 6779 are new photometric candidates). Our algorithm is more complete to z>3.5 than the traditional mid-IR selection "wedges" and to 2.2<z<3.5 quasars than the SDSS-III/BOSS project. Number counts and luminosity function analysis suggest that the resulting catalog is relatively complete to known quasars and is identifying new high-z quasars at z>3. This catalog paves the way for luminosity-dependent clustering investigations of large numbers of faint, high-redshift quasars and for further machine-learning quasar selection using Spitzer and WISE data combined with other large-area optical imaging surveys.
- ID:
- ivo://CDS.VizieR/J/MNRAS/406/1583
- Title:
- Quasar from SDSS and UKIDSS
- Short Name:
- J/MNRAS/406/1583
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a sample of 8498 quasars with both Sloan Digital Sky Survey (SDSS) ugriz optical and United Kingdom Infrared Telescope (UKIRT) Infrared Deep Sky Survey (UKIDSS) YJHK near-infrared (near-IR) photometric data. With this sample, we obtain the median colour-z relations based on 7400 quasars with magnitude uncertainties less than 0.1mag in all bands. By analysing the quasar colours, we propose an empirical criterion in the Y-K versus g-z colour-colour diagram to separate stars and quasars with redshift z<4, and two other criteria for selecting high-redshift quasars. Using the SDSS-UKIDSS colour-z relations, we estimate the photometric redshifts of 8498 SDSS-UKIDSS quasars, and find that 85.0 per cent of them are consistent with the spectroscopic redshifts within |{Delta}z|<0.2, which leads to a significant increase of the photometric redshift accuracy from that based on the SDSS colour-z relations only. As two tests, we compare our colour-selection criterion with a small UKIDSS/EDR quasar/star sample and a sample of 4671 variable sources in the SDSS Stripe 82 region with both SDSS and UKIDSS data. We find that they can be clearly divided into two classes (quasars and stars) by our criterion in the Y-K versus g-z plot.
- ID:
- ivo://CDS.VizieR/J/AJ/131/2766
- Title:
- Quasar luminosity function from SDSS-DR3
- Short Name:
- J/AJ/131/2766
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We determine the number counts and z=0-5 luminosity function for a well-defined, homogeneous sample of quasars from the Sloan Digital Sky Survey (SDSS). We conservatively define the most uniform statistical sample possible, consisting of 15343 quasars within an effective area of 1622{deg}^2^ that was derived from a parent sample of 46420 spectroscopically confirmed broad-line quasars in the 5282{deg}^2^ of imaging data from SDSS Data Release 3. The sample extends from i=15 to 19.1 at z<~3 and to i=20.2 for z>~3.
