- ID:
- ivo://CDS.VizieR/J/MNRAS/440/365
- Title:
- Galactic Bulge accreting binaries spectroscopy
- Short Name:
- J/MNRAS/440/365
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the identification of optical counterparts to 23 GBS X-ray sources. All sources are classified as accreting binaries according to the emission-line characteristics inferred from medium-resolution spectroscopy. To distinguish accreting binaries from chromospherically active objects, we develop criteria based on H{alpha} and HeI {lambda}{lambda}5786, 6678 emission-line properties available in the literature. The spectroscopic properties and photometric variability of each object is discussed and a classification is given where possible. At least 12 of the 23 systems show an accretion-dominated optical spectrum and another 6 show stellar absorption features in addition to emission lines indicating that they are probably accreting binaries in quiescence or in a low accretion rate state. Two sources are confirmed to be eclipsing: CX207 and CX794. CX207 is likely a magnetic cataclysmic variable (CV), while CX794 is a nova-like CV in the period gap. Finally, the large broadening (2100km/s FWHM) of the H{alpha} emission lines in CX446 and CX1004 suggests that they are also high-inclination or even eclipsing systems. Whether the compact object is a white dwarf in an eclipsing CV, a neutron star or a black hole in a high-inclination low-mass X-ray binary remains to be established.
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Search Results
- ID:
- ivo://CDS.VizieR/J/AJ/153/99
- Title:
- Galactic outer disk: a field toward Tombaugh 1
- Short Name:
- J/AJ/153/99
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We employ optical photometry and high-resolution spectroscopy to study a field toward the open cluster Tombaugh 1, where we identify a complex population mixture that we describe in terms of young and old Galactic thin disks. Of particular interest is the spatial distribution of the young population, which consists of dwarfs with spectral types as early as B6 and is distributed in a blue plume feature in the color-magnitude diagram. For the first time, we confirm spectroscopically that most of these stars are early-type stars and not blue stragglers or halo/thick-disk subdwarfs. Moreover, they are not evenly distributed along the line of sight but crowd at heliocentric distances between 6.6 and 8.2 kpc. We compare these results with present-day understanding of the spiral structure of the Galaxy and suggest that they trace the outer arm. This range of distances challenges current Galactic models adopting a disk cutoff at 14 kpc from the Galactic center. The young dwarfs overlap in space with an older component, which is identified as an old Galactic thin disk. Both young and old populations are confined in space since the disk is warped at the latitude and longitude of Tombaugh 1. The main effects of the warp are that the line of sight intersects the disk and entirely crosses it at the outer arm distance and that there are no traces of the closer Perseus arm, which would then be either unimportant in this sector or located much closer to the formal Galactic plane. Finally, we analyze a group of giant stars, which turn out to be located at very different distances and to possess very different chemical properties, with no obvious relation to the other populations.
- ID:
- ivo://CDS.VizieR/J/ApJ/853/95
- Title:
- Galaxies probing galaxies in PRIMUS. I.
- Short Name:
- J/ApJ/853/95
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The spectroscopy of background QSO sightlines passing close to foreground galaxies is a potent technique for studying the circumgalactic medium (CGM). However, QSOs are effectively point sources, limiting their potential to constrain the size of circumgalactic gaseous structures. Here we present the first large Keck/Low-resolution Imaging Spectrometer (LRIS) and Very Large Telescope (VLT)/Focal Reducer/Low-dispersion Spectrograph 2 (FORS2) spectroscopic survey of bright (B_AB_<22.3) background galaxies whose lines of sight probe MgII{lambda}{lambda}2796,2803 absorption from the CGM around close projected foreground galaxies at transverse distances 10kpc<R_{perp}_<150kpc. Our sample of 72 projected pairs, drawn from the PRIsm MUlti-object Survey, includes 48 background galaxies that do not host bright active galactic nuclei, and both star-forming and quiescent foreground galaxies with stellar masses of 9.0<logM_*_/M_{sun}_<11.2 at redshifts of 0.35<z_f/g_<0.8. We detect MgII absorption associated with these foreground galaxies with equivalent widths of 0.25{AA}<W_2796_<2.6{AA} at >2{sigma} significance in 20 individual background sightlines passing within R_{perp}_<50kpc and place 2{sigma} upper limits on W_2796_ of <~0.5{AA} in an additional 11 close sightlines. Within R_{perp}_<50kpc, W_2796_ is anticorrelated with R_{perp}_, consistent with analyses of Mg ii absorption detected along background QSO sightlines. Subsamples of these foreground hosts divided at logM_*_/M_{sun}_=9.9 exhibit statistically inconsistent W_2796_ distributions at 30kpc<R_{perp}_<50kpc, with the higher-M* galaxies yielding a larger median W_2796_ by 0.9{AA}. Finally, we demonstrate that foreground galaxies with similar stellar masses exhibit the same median W_2796_ at a given R_{perp}_ to within <0.2{AA} toward both background galaxies and toward QSO sightlines drawn from the literature. Analysis of these data sets constraining the spatial coherence scale of circumgalactic MgII absorption is presented in a companion paper.
- ID:
- ivo://CDS.VizieR/J/AJ/138/873
- Title:
- Galaxies with H{alpha} emission in A2151
- Short Name:
- J/AJ/138/873
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This paper presents the first results of an H{alpha} imaging survey of galaxies in the central regions of the A2151 cluster. A total of 50 sources were detected in H{alpha}, from which 41 were classified as secure members of the cluster and 2 as likely members based on spectroscopic and photometric redshift considerations. The remaining seven galaxies were classified as background contaminants and thus excluded from our study on the H{alpha} properties of the cluster.
- ID:
- ivo://CDS.VizieR/J/ApJ/679/1144
- Title:
- Galaxy clusters in LOS to background QSOs. I.
- Short Name:
- J/ApJ/679/1144
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We describe the first optical survey of absorption systems associated with cluster galaxies at z=0.3-0.9. We have cross-correlated quasars from the third data release of the SDSS (Cat. VII/243) with high-redshift cluster/group candidates from the Red-Sequence Cluster Survey (Cat. J/ApJS/157/1). We have found 442 quasar-cluster pairs for which the MgII{lambda}2796, 2803 doublet might be detected at a transverse (physical) distance d<2h^-1^_71_Mpc from the cluster centers. To investigate the incidence dN/dz and equivalent width distribution n(W) of MgII systems at cluster redshifts, two statistical samples were drawn out of these pairs: one made of high-resolution spectroscopic quasar observations (46 pairs), and one made of quasars used in MgII searches found in the literature (375 pairs).
- ID:
- ivo://CDS.VizieR/J/MNRAS/337/256
- Title:
- Galaxy in low X-ray luminosity clusters
- Short Name:
- J/MNRAS/337/256
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the first spectroscopic survey of intrinsically low X-ray luminosity clusters at z>>0, with Hubble Space Telescope (HST) WFPC2 imaging and spectroscopy from Calar Alto and WHT-LDSS2. We study 172 confirmed cluster members in a sample of ten clusters at 0.23<z<0.3, with LX<~4x10^43^h^-2^erg/s[0.1-2.4keV]. The core of each cluster is imaged with WFPC2 in the F702W filter, and the spectroscopic sample is statistically complete to Mr~-19.0+5logh, within an 11' (~1.8h^-1^Mpc) field. The clusters are dynamically well-separated from the surrounding field and most have velocity distributions consistent with Gaussians. The velocity dispersions range from 350-850km/s, consistent with the local L_X_-{sigma} correlation. All 10 clusters host a bright, giant elliptical galaxy without emission lines, near the centre of the X-ray emission. We measure the equivalent width of two nebular emission lines, [O II] and H{alpha}, and the H{delta} absorption line to classify the cluster members spectrally. Galaxy morphologies are measured from the HST images, using the two-dimensional surface-brightness fitting software GIM2D.
- ID:
- ivo://CDS.VizieR/J/A+A/527/A101
- Title:
- Galaxy population of Abell 1367
- Short Name:
- J/A+A/527/A101
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Spectroscopic and photometric data of the galaxy population of the galaxy cluster Abell 1367, over a field of 34'x90', covering the cluster centre out to a radius of ~2.2Mpc, are presented as the first stage of a study of their stellar population and star formation properties. Spectroscopic catalogue contains new detection data of emission and/or absorption lines for 84 galaxies in our survey regions. Photometric data give optical and near-infrared isophotal magnitudes for 303 galaxies, determined within R_24_ isophotal diameters. H{alpha} emission catalogue reports equivalent widths and fluxes of 72 galaxies, confirmed as cluster members of Abell 1367.
- ID:
- ivo://CDS.VizieR/J/A+A/586/A67
- Title:
- G64-12 and G64-37 linelist and EWs
- Short Name:
- J/A+A/586/A67
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Studies of extremely metal-poor stars indicate that chemical abundance ratios [X/Fe] have a root mean square scatter as low as 0.05dex (12%). It remains unclear whether this reflects observational uncertainties or intrinsic astrophysical scatter arising from physical conditions in the ISM at early times. We measure differential chemical abundance ratios in extremely metal-poor stars to investigate the limits of precision and to understand whether cosmic scatter or observational errors are dominant. We used high-resolution (R~95000) and high signal-to-noise (S/N=700 at 5000{AA}) HIRES/Keck spectra to determine high-precision differential abundances between two extremely metal-poor stars through a line-by-line differential approach. We determined stellar parameters for the star G64-37 with respect to the standard star G64-12. We performed EW measurements for the two stars for the lines recognized in both stars and performed spectral synthesis to study the carbon abundances. Results. The differential approach allowed us to obtain errors of {sigma}(Teff)=27K, {sigma}(logg)=0.06dex, {sigma}([Fe/H])=0.02dex and {sigma}(vt)=0.06km/s. We estimated relative chemical abundances with a precision as low as {sigma}([X/Fe])~0.01dex. The small uncertainties demonstrate that there are genuine abundance differences larger than the measurement errors. The observed Li difference cannot be explained by the difference in mass because the less massive star has more Li. It is possible to achieve an abundance precision around ~0.01-0.05dex for extremely metal-poor stars, which opens new windows on the study of the early chemical evolution of the Galaxy.
- ID:
- ivo://CDS.VizieR/J/PASP/125/477
- Title:
- Gas Survey of Protoplanetary Systems. I.
- Short Name:
- J/PASP/125/477
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We describe a large-scale far-infrared line and continuum survey of protoplanetary disk through to young debris disk systems carried out using the ACS instrument on the Herschel Space Observatory. This Open Time Key program, known as GASPS (Gas Survey of Protoplanetary Systems), targeted ~250 young stars in narrow wavelength regions covering the [OI] fine structure line at 63um the brightest far-infrared line in such objects. A subset of the brightest targets were also surveyed in [OI]145um, [CII] at 157um, as well as several transitions of HO and high-excitation CO lines at selected wavelengths between 78 and 180um. Additionally, GASPS included continuum photometry at 70, 100 and 160um, around the peak of the dust emission.
- ID:
- ivo://CDS.VizieR/J/MNRAS/443/2679
- Title:
- GEEC2 spectroscopic survey of Galaxy groups
- Short Name:
- J/MNRAS/443/2679
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the data release of the Gemini-South GMOS spectroscopy in the fields of 11 galaxy groups at 0.8<z<1, within the COSMOS field. This forms the basis of the Galaxy Environment Evolution Collaboration 2 (GEEC2) project to study galaxy evolution in haloes with M~10^13^M_{sun}_ across cosmic time. The final sample includes 162 spectroscopically confirmed members with R<24.75, and is >50% complete for galaxies within the virial radius, and with stellar mass M_star_>10^10.3^M_{sun}_. Including galaxies with photometric redshifts, we have an effective sample size of ~400 galaxies within the virial radii of these groups. We present group velocity dispersions, dynamical and stellar masses. Combining with the GCLASS sample of more massive clusters at the same redshift, we find the total stellar mass is strongly correlated with the dynamical mass, with logM_200_=1.20(logM_star_-12)+14.07. This stellar fraction of ~1% is lower than predicted by some halo occupation distribution models, though the weak dependence on halo mass is in good agreement. Most groups have an easily identifiable most massive galaxy (MMG) near the centre of the galaxy distribution, and we present the spectroscopic properties and surface brightness fits to these galaxies. The total stellar mass distribution in the groups, excluding the MMG, compares well with an NFW (Navarro Frenk & White) profile with concentration 4, for galaxies beyond ~0.2R_200_. This is more concentrated than the number density distribution, demonstrating that there is some mass segregation.
