- ID:
- ivo://CDS.VizieR/J/A+A/402/1157
- Title:
- Photometric standards around gravitational lenses
- Short Name:
- J/A+A/402/1157
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a catalog of secondary photometric standard stars in the neighborhood of 14 gravitationally lensed quasars. These stars were verified to be non variable using long-term monitoring. The instrumental magnitudes of the new standard stars have been transformed to the Johnson-Cousins BV(RI)c photometric system. For ten gravitational lenses (GLs) we also provide the BV(RI)c mean magnitudes of the integrated flux of all the lens components, for the epochs of the photometric calibration.
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Search Results
- ID:
- ivo://CDS.VizieR/J/A+A/458/225
- Title:
- Photometric standard stars in the field of GR 290
- Short Name:
- J/A+A/458/225
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Understanding the origin of the instabilities of LBVs is important for shedding light on the late evolutionary stages of massive stars and on the chemical evolution of galaxies. To investigate the physical nature of variable stars in the upper H-R diagram, we performed a spectrophotometric study of the Romano's star GR 290 and the Hubble-Sandage variables A, B, and C in the close galaxy M 33. New spectroscopic and photometric data were employed in conjunction with already published data of these stars in order to derive spectral types, energy distribution and bolometric luminosities.
- ID:
- ivo://CDS.VizieR/J/AJ/154/30
- Title:
- Photometric study of fourteen low-mass binaries
- Short Name:
- J/AJ/154/30
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- New CCD photometric observations of fourteen short-period low-mass eclipsing binaries (LMBs) in the photometric filters I, R, and V were used for a light curve analysis. A discrepancy remains between observed radii and those derived from the theoretical modeling for LMBs, in general. Mass calibration of all observed LMBs was performed using only the photometric indices. The light curve modeling of these selected systems was completed, yielding the new derived masses and radii for both components. We compared these systems with the compilation of other known double-lined LMB systems with uncertainties of masses and radii less then 5%, which includes 66 components of binaries where both spectroscopy and photometry were combined together. All of our systems are circular short-period binaries, and for some of them, the photospheric spots were also used. A purely photometric study of the light curves without spectroscopy seems unable to achieve high enough precision and accuracy in the masses and radii to act as meaningful test of the M-R relation for low-mass stars.
- ID:
- ivo://CDS.VizieR/J/MNRAS/475/1633
- Title:
- Photometric study of globular clusters
- Short Name:
- J/MNRAS/475/1633
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In this paper, we describe the photometric and spectroscopic properties of multiple populations in seven northern globular clusters. In this study, we employ precise ground-based photometry from the private collection of Stetson, space photometry from the Hubble Space Telescope (HST), literature abundances of Na and O, and Apache Point Observatory Galactic Evolution Experiment (APOGEE) survey abundances for Mg, Al, C, and N. Multiple populations are identified by their position in the C_U,B,I_-V pseudo colour-magnitude diagram (pseudo-CMD) and confirmed with their chemical composition determined using abundances. We confirm the expectation from previous studies that the red giant branches (RGBs) in all seven clusters are split and the different branches have different chemical compositions. The Mg-Al anticorrelations were well explored by the APOGEE and Gaia-ESO surveys for most globular clusters, some clusters showing bimodal distributions, while others continuous distributions. Even though the structure (i.e. bimodal versus continuous) of Mg-Al can greatly vary, the Al-rich and Al-poor populations do not seem to have very different photometric properties, agreeing with theoretical calculations. There is no one-to-one correspondence between the Mg-Al anticorrelation shape (bimodal versus continuous) and the structure of the RGB seen in the HST pseudo-CMDs, with the HSTphotometric information usually implying more complex formation/evolution histories than the spectroscopic ones. We report on finding two second-generation horizontal branch (HB) stars in M5, and five second-generation asymptotic giant branch (AGB) stars in M92, which is the most metal-poor cluster to date in which second-generation AGB stars have been observed.
- ID:
- ivo://CDS.VizieR/J/AJ/131/1891
- Title:
- Photometric survey of MS 1054-03 field
- Short Name:
- J/AJ/131/1891
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present deep near-infrared Js-, H-, and Ks-band imaging of a field around MS 1054-03, a massive cluster at z=0.83. The observations were carried out with the ISAAC instrument at the ESO Very Large Telescope (VLT) as part of the Faint Infrared Extragalactic Survey (FIRES). The total integration time amounts to 25.9hr in Js, 24.4hr in H, and 26.5hr in Ks, divided nearly equally between four pointings covering 5.5'x5.3'. The 3 total limiting AB magnitudes for point sources from the shallowest to the deepest pointing are J^tot^_s,AB_=26.0-26.2, H^tot^_AB_=25.5-25.8, and K^tot^_s,AB_=25.3-25.7mag. The effective spatial resolution of the co-added images has FWHM=0.48", 0.46", and 0.52" in Js, H, and Ks, respectively. We complemented the ISAAC data with deep optical imaging using existing Hubble Space Telescope WFPC2 mosaics through the F606W and F814W filters and additional U-, B-, and V-band observations we obtained with the VLT FORS1 instrument. We constructed a Ks-band-limited multicolor source catalog down to K^tot^_s,AB_~25mag (~5{sigma} for point sources). The catalog contains 1858 objects, of which 1663 have eight-band photometry. We describe the observations, data reduction, source detection, and photometric measurements method. We also present the number counts, color distributions, and photometric redshifts zph of the catalog sources. We find that our Ks-band counts at the faint end 22<~K_s,AB_<~25, with slope dlogN/dm=0.20, lie at the flatter end of published counts in other deep fields and are consistent with those we derived previously in the Hubble Deep Field-South (HDF-S), the other FIRES field. Spectroscopic redshifts zsp are available for ~330 sources in the MS 1054-03 field; comparison between zph and zsp shows very good agreement, with <|zsp-zph|/(1+zsp)>=0.078. The MS 1054-03 field observations complement our HDF-S data set with a nearly 5 times larger area at ~0.7mag brighter limits, providing more robust statistics for the slightly brighter source populations.
- ID:
- ivo://CDS.VizieR/J/AJ/153/252
- Title:
- Photometric variability of BeSS-KELT stars
- Short Name:
- J/AJ/153/252
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Be stars have generally been characterized by the emission lines in their spectra, and especially the time variability of those spectroscopic features. They are known to also exhibit photometric variability at multiple timescales, but have not been broadly compared and analyzed by that behavior. We have taken advantage of the advent of wide-field, long-baseline, and high-cadence photometric surveys that search for transiting exoplanets to perform a comprehensive analysis of brightness variations among a large number of known Be stars. The photometric data comes from the KELT transit survey, with a typical cadence of 30 minutes, a baseline of up to 10 years, photometric precision of about 1%, and coverage of about 60% of the sky. We analyze KELT light curves of 610 known Be stars in both the northern and southern hemispheres in an effort to study their variability. Consistent with other studies of Be star variability, we find most of the stars to be photometrically variable. We derive lower limits on the fraction of stars in our sample that exhibit features consistent with non-radial pulsations (25%), outbursts (36%), and long-term trends in the circumstellar disk (37%), and show how these are correlated with spectral sub-types. Other types of variability, such as those owing to binarity, are also explored. Simultaneous spectroscopy for some of these systems from the Be Star Spectra database allow us to better understand the physical causes for the observed variability, especially in cases of outbursts and changes in the disk.
- ID:
- ivo://CDS.VizieR/J/ApJS/218/20
- Title:
- Photometric variability search in the CSTAR field
- Short Name:
- J/ApJS/218/20
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Chinese Small Telescope Array (CSTAR) is the first telescope facility built at Dome A, Antarctica. During the 2008 observing season, the installation provided long-baseline and high-cadence photometric observations in the i-band for 18145 targets within 20deg^2^ CSTAR field around the South Celestial Pole for the purpose of monitoring the astronomical observing quality of Dome A and detecting various types of photometric variability. Using sensitive and robust detection methods, we discover 274 potential variables from this data set, 83 of which are new discoveries. We characterize most of them, providing the periods, amplitudes, and classes of variability.
- ID:
- ivo://CDS.VizieR/J/A+A/448/893
- Title:
- Photometry and lines of (z~0.2-1.0) galaxies
- Short Name:
- J/A+A/448/893
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the spectrophotometric properties of a sample of 141 emission-line galaxies at redshifts in the range 0.2<z<1.0 with a peak around 0.2<=z<=0.4. The analysis is based on medium resolution (Rs=500-600), optical spectra obtained at VLT and Keck. The targets are mostly "Canada-France Redshift Survey" (<VII/225>) emission-line galaxies, with the addition of field galaxies randomly selected behind lensing clusters. We complement this sample with galaxy spectra from the "Gemini Deep Deep Survey" (<J/AJ/127/2455>) public data release. We have computed absolute magnitudes of the galaxies and measured the line fluxes and equivalent widths of the main emission/absorption lines. The last two have been measured after careful subtraction of the fitted stellar continuum using the platefit software originally developed for the SDSS and adapted to our data. We present a careful comparison of this software with the results of manual measurements.
- ID:
- ivo://CDS.VizieR/J/A+A/578/A4
- Title:
- Photometry and motions in Arches and Quintuplet
- Short Name:
- J/A+A/578/A4
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We investigate the circumstellar disc fraction as determined from L-band excess observations of the young, massive Arches and Quintuplet clusters residing in the central molecular zone of the Milky Way. The Quintuplet cluster was searched for L-band excess sources for the first time. We find a total of 26 excess sources in the Quintuplet cluster, and 21 sources with L-band excesses in the Arches cluster, of which 13 are new detections. With the aid of proper motion membership samples, the disc fraction of the Quintuplet cluster could be derived for the first time to be 4.0+/-0.7. There is no evidence for a radially varying disc fraction in this cluster. In the case of the Arches cluster, a disc fraction of 9.2+/-1.2 approximately out to the cluster's predicted tidal radius, r<1.5pc (Habibi et al., 2013A&A...556A..26H, Cat. J/A+A/556/A26), is found. This excess fraction is consistent with our previously found disc fraction in the cluster in the radial range 0.3<r<0.8pc. In both clusters, the host star mass range covers late A to early B-type stars, 2<M<15M_{sun}, as derived from J-band photospheric magnitudes. We discuss the unexpected finding of dusty circumstellar discs in these UV intense environments in the context of primordial disc survival and formation scenarios of secondary discs. We consider the possibility that the L-band excess sources in the Arches and Quintuplet clusters could be the high-mass counterparts to T Tauri pre-transitional discs. As such a scenario requires a long pre-transitional disc lifetime in a UV intense environment, we suggest that mass transfer discs in binary systems are a likely formation mechanism for the B-star discs observed in these starburst clusters.
- ID:
- ivo://CDS.VizieR/J/AZh/78/60
- Title:
- Photometry and polarimetry of Ae star VV Ser
- Short Name:
- J/AZh/78/60
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Results of long-term photometric and polarimetric observations of the classical Herbig Ae star VV Ser, performed at the Crimean Astrophysical Observatory as part of a program of photometric and polarimetric monitoring of UX Ori stars are presented.
