- ID:
- ivo://CDS.VizieR/J/MNRAS/492/L40
- Title:
- Disentangling cataclysmic variables in Gaia DR2
- Short Name:
- J/MNRAS/492/L40
- Date:
- 07 Dec 2021 09:36:41
- Publisher:
- CDS
- Description:
- Cataclysmic Variables (CVs) are interacting binaries consisting of at least three components that control their colour and magnitude. Using Gaia we here investigate the influence of the physical properties of these binaries on their position in the Hertzsprung-Russell diagram (HR-diagram). The CVs are on average located between the main sequence and the white dwarf regime, the maximum density being at G_BP_-G_RP_~=0.56 and G_abs_~10.15. We nd a trend of the orbital period with colour and absolute brightness: with decreasing period, the CVs become bluer and fainter. We also identify the location of the various CV sub-types in the HR-diagram and discuss the possible location of detached CVs, going through the orbital period gap.
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Search Results
- ID:
- ivo://CDS.VizieR/J/ApJS/256/46
- Title:
- Distances & color excesses of high gal. mol. clouds
- Short Name:
- J/ApJS/256/46
- Date:
- 03 Mar 2022 14:08:03
- Publisher:
- CDS
- Description:
- Based on the accurate color excess E_GBP,GRP_ of more than 4 million stars and the E_NUV,GBP_ of more than 1 million stars from Paper I (Sun+, 2021ApJS..254...38S), the distance and extinction of the molecular clouds (MCs) in the Magnani-Blitz-Mundy (MBM; 1985ApJ...295..402M) catalog at |b|>20{deg} are studied in combination with the distance measurement of Gaia/EDR3. The distance, as well as the color excess, is determined for 66 MCs. The color excess ratio E_NUV,GBP_/E_GBP,GRP_ is derived for 39 of them, which is obviously larger and implies more small particles at smaller extinction. In addition, the scale height of the dust disk is found to be about 100 pc and becomes large at the anticenter direction due to the disk flaring.
- ID:
- ivo://CDS.VizieR/J/AJ/136/2107
- Title:
- Distances of cataclysmic variables
- Short Name:
- J/AJ/136/2107
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report parallax and distance estimates for 12 more cataclysmic binaries and related objects observed with the 2.4m Hiltner telescope at MDM Observatory. The final parallax accuracy is typically ~1mas.
- ID:
- ivo://CDS.VizieR/J/AJ/126/3017
- Title:
- Distances of Cataclysmic variables
- Short Name:
- J/AJ/126/3017
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The 2.4m Hiltner Telescope at MDM Observatory was used in an attempt to measure trigonometric parallaxes for 14 cataclysmic variable stars. Techniques are described in detail. In the best cases the parallax uncertainties are below 1mas, and significant parallaxes are found for most of the program stars. A Bayesian method that combines the parallaxes together with proper motions and absolute magnitude constraints is developed and used to derive distance estimates and confidence intervals. The most precise distance derived here is for WZ Sge, for which is found to be 43.3^+1.6^_-1.5_pc. Six Luyten Half-Second stars with previous precise parallax measurements were remeasured to test the techniques, and good agreement was found.
- ID:
- ivo://CDS.VizieR/J/ApJ/833/119
- Title:
- Distances of Gaia DR1 TGAS sources
- Short Name:
- J/ApJ/833/119
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We infer distances and their asymmetric uncertainties for two million stars using the parallaxes published in the Gaia DR1 (GDR1) catalogue. We do this with two distance priors: A minimalist, isotropic prior assuming an exponentially decreasing space density with increasing distance, and an anisotropic prior derived from the observability of stars in a Milky Way model. We validate our results by comparing our distance estimates for 105 Cepheids which have more precise, independently estimated distances. For this sample we find that the Milky Way prior performs better (the RMS of the scaled residuals is 0.40) than the exponentially decreasing space density prior (RMS is 0.57), although for distances beyond 2kpc the Milky Way prior performs worse, with a bias in the scaled residuals of -0.36 (vs. -0.07 for the exponentially decreasing space density prior). We do not attempt to include the photometric data in GDR1 due to the lack of reliable colour information. Our distance catalogue is available at http://www.mpia.de/homes/calj/tgas_distances/main.html. These should only be used to give individual distances. Combining data or testing models should be done with the original parallaxes, and attention paid to correlated and systematic uncertainties.
- ID:
- ivo://CDS.VizieR/J/ApJ/571/512
- Title:
- Distances of white dwarf stars
- Short Name:
- J/ApJ/571/512
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The most recent version of the Catalog of Spectroscopically Identified White Dwarfs lists 2249 white dwarf stars. Among these stars are 109 white dwarfs that have either reliable trigonometric parallaxes or color-based distance moduli that place them at a distance within 20pc of the Sun. Most of these nearby white dwarfs are isolated stars, but 28 (25% of the sample) are in binary systems, including such well-known systems as Sirius A/B and Procyon A/B. There are also three double degenerate systems in this sample of the local white dwarf population. The sample of local white dwarfs is largely complete out to 13pc, and the local density of white dwarf stars is found to be 5.0+/-0.7x10^-3^pc^-3^, with a corresponding mass density of 3.4+/-0.5x10^-3^M{sun}_/pc^3^
- ID:
- ivo://CDS.VizieR/J/A+A/607/A56
- Title:
- Distant clusters of galaxies in the 2XMM/SDSS
- Short Name:
- J/A+A/607/A56
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Galaxy clusters at high redshift are important to test cosmological models and models for the growth of structure. They are difficult to find in wide-angle optical surveys, however, leaving dedicated follow-up of X-ray selected candidates as one promising identification route. We aim to increase the number of galaxy clusters beyond the SDSS-limit, z~0.75. We compiled a list of extended X-ray sources from the 2XMMp catalogue within the footprint of the Sloan Digital Sky Survey. Fields without optical counterpart were selected for further investigation. Deep optical imaging and follow-up spectroscopy were obtained with the Large Binocular Telescope, Arizona (LBT), of those candidates not known to the literature. From initially 19 candidates, selected by visually screening X-ray images of 478 XMM-Newton observations and the corresponding SDSS images, 6 clusters were found in the literature. Imaging data through r,z filters were obtained for the remaining candidates, and 7 were chosen for multi-object (MOS) spectroscopy. Spectroscopic redshifts, optical magnitudes, and X-ray parameters (flux, temperature, and luminosity) are presented for the clusters with spectroscopic redshifts. The distant clusters studied here constitute one additional redshift bin for studies of the L-T relation, which does not seem to evolve from high to low redshifts. The selection method of distant galaxy clusters presented here was highly successful. It is based solely on archival optical (SDSS) and X-ray (XMM-Newton) data. Out of 19 selected candidates, 6 of the 7 candidates selected for spectroscopic follow-up were verified as distant clusters, a further candidate is most likely a group of galaxies at z~1.21. Out of the remaining 12 candidates, 6 were known previously as galaxy clusters, one object is a likely X-ray emission from an AGN radio jet, and for 5 we see no clear evidence for them to be high-redshift galaxy clusters.
- ID:
- ivo://CDS.VizieR/J/ApJS/142/153
- Title:
- Distant galaxy clusters photometry
- Short Name:
- J/ApJS/142/153
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present optical and near-infrared photometry of 45 clusters of galaxies at 0.1<z<1.3. Galaxy catalogs in each cluster were defined at the longest wavelength available, generally the K band, down to approximately 2mag below M*. We include finding chart images of the band used for catalog definition. The photometry has been used in previously published papers to examine the origin and evolution of galaxies in distant clusters. Beginning in 1991, we sought to make use of the advent of relatively large format near-IR detectors to study the galaxy populations of distant clusters. We collected imaging data in both the near-IR and the optical on a large sample of clusters drawn from several samples. These data were analyzed and detailed results were presented on the evolution of early-type galaxies at moderate redshifts in Stanford, Eisenhardt, & Dickinson (1995ApJ...450..512S, 1998ApJ...492..461S), on the evolution of the K-band luminosity function in De Propris et al. (1999AJ....118..719D), on the Butcher-Oemler effect in K-selected galaxy samples in De Propris et al. (2003, ApJ, submitted), and on the evolution of early-type galaxies in high-redshift clusters in Holden et al. (2003, ApJ, in press). So far the photometry for these various studies has been published for only two clusters, Abell 370 and Abell 851 in Stanford et al. (1995ApJ...450..512S). In this paper, we present the photometry on the other 43 clusters used in our published work on distant clusters.
- ID:
- ivo://CDS.VizieR/J/PASP/105/1465
- Title:
- Distant OB Stars in the Galaxy
- Short Name:
- J/PASP/105/1465
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Distances and reddenings have been computed from UBVbeta photometry for 1044 stars in the Stephenson and Sanduleak (1971) "Catalog of Luminous Stars in the Southern Milky Way".
- ID:
- ivo://CDS.VizieR/J/ApJ/855/43
- Title:
- Distant RR Lyrae stars discovered with HiTS
- Short Name:
- J/ApJ/855/43
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the discovery of distant RR Lyrae stars, including the most distant known in the Milky Way, using data taken in the g-band with the Dark Energy Camera as part of the High cadence Transient Survey (HiTS; 2014 campaign). We detect a total of 173 RR Lyrae stars over a ~120deg^2^ area, including both known RR Lyrae and new detections. The heliocentric distances dH of the full sample range from 9 to >200kpc, with 18 of them beyond 90kpc. We identify three sub-groups of RR Lyrae as members of known systems: the Sextans dwarf spheroidal galaxy, for which we report 46 new discoveries, and the ultra-faint dwarf galaxies Leo IV and Leo V. Following an MCMC methodology, we fit spherical and ellipsoidal profiles of the form {rho}(R)~Rn to the radial density distribution of RR Lyrae in the Galactic halo. The best fit corresponds to the spherical case, for which we obtain a simple power-law index of n=-4.17_-0.20_^+0.18^, consistent with recent studies made with samples covering shorter distances. The pulsational properties of the outermost RR Lyrae in the sample (dH>90kpc) differ from the ones in the halo population at closer distances. The distribution of the stars in a period-amplitude diagram suggest they belong to Oosterhoff-intermediate or Oosterhoff II groups, similar to what is found in the ultra-faint dwarf satellites around the Milky Way. The new distant stars discovered represent an important addition to the few existing tracers of the Milky Way potential in the outer halo.
