Search

Start Over Subject photometry Capability Type Simple Cone Search
1071. Cr, Co, and Ni abundances for metal-poor red giants
ID:
ivo://CDS.VizieR/J/ApJS/237/18
Title:
Cr, Co, and Ni abundances for metal-poor red giants
Short Name:
J/ApJS/237/18
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present measurements of the abundances of chromium, cobalt, and nickel in 4113 red giants, including 2277 stars in globular clusters (GCs), 1820 stars in the Milky Way's dwarf satellite galaxies, and 16 field stars. We measured the abundances from mostly archival Keck/DEIMOS medium-resolution spectroscopy with a resolving power of R~6500 and a wavelength range of approximately 6500-9000{AA}. The abundances were determined by fitting spectral regions that contain absorption lines of the elements under consideration. We used estimates of temperature, surface gravity, and metallicity that we previously determined from the same spectra. We estimated systematic error by examining the dispersion of abundances within mono- metallic GCs. The median uncertainties for [Cr/Fe], [Co/Fe], and [Ni/Fe] are 0.20, 0.20, and 0.13, respectively. Finally, we validated our estimations of uncertainty through duplicate measurements, and we evaluated the accuracy and precision of our measurements through comparison to high-resolution spectroscopic measurements of the same stars.
1072. CRIc photometry of Magellanic Bridge Fields
ID:
ivo://CDS.VizieR/J/ApJ/658/345
Title:
CRIc photometry of Magellanic Bridge Fields
Short Name:
J/ApJ/658/345
Date:
21 Oct 2021
Publisher:
CDS
Description:
We report on observations of the stellar populations in 12 fields spanning the region between the Magellanic Clouds, made with the Mosaic II camera on the 4m telescope at the Cerro-Tololo Inter-American Observatory. The two main goals of the observations are to characterize the young stellar population (which presumably formed in situ in the Bridge and therefore represents the nearest stellar population formed from tidal debris), and to search for an older stellar component (which would have been stripped from either Cloud as stars, by the same tidal forces that formed the gaseous Bridge). We determine the star formation history of the young inter-Cloud population, which provides a constraint on the timing of the gravitational interaction that formed the Bridge. We do not detect an older stellar population belonging to the Bridge in any of our fields, implying that the material that was stripped from the Clouds to form the Magellanic Bridge was very nearly a pure gas.
1073. CSP-I photometry for 34 supernovae
ID:
ivo://CDS.VizieR/J/A+A/609/A134
Title:
CSP-I photometry for 34 supernovae
Short Name:
J/A+A/609/A134
Date:
21 Oct 2021
Publisher:
CDS
Description:
The first phase of the Carnegie Supernova Project (CSP-I) was a dedicated supernova follow-up program based at the Las Campanas Observatory that collected science data of young, low-redshift supernovae between 2004 and 2009. Presented in this paper is the CSP-I photometric data release of low-redshift stripped-envelope core-collapse supernovae. The data consist of optical (uBgV ri) photometry of 34 objects, with a subset of 26 having near-infrared (YJH) photometry. Twenty objects have optical pre-maximum coverage with a subset of 12 beginning at least five days prior to the epoch of B-band maximum brightness. In the near-infrared, 17 objects have pre-maximum observations with a subset of 14 beginning at least five days prior to the epoch of J-band maximum brightness. Analysis of this photometric data release is presented in companion papers focusing on techniques to estimate host-galaxy extinction (Stritzinger et al., submitted) and the light-curve and progenitor star properties of the sample (Taddia et al., submitted). The analysis of an accompanying visual-wavelength spectroscopy sample of ~150 spectra will be the subject of a future paper.
1074. CSS Periodic Variable Star Catalogue
ID:
ivo://CDS.VizieR/J/MNRAS/469/3688
Title:
CSS Periodic Variable Star Catalogue
Short Name:
J/MNRAS/469/3688
Date:
21 Oct 2021
Publisher:
CDS
Description:
Here we present the results from our analysis of six years of optical photometry taken by the Siding Spring Survey (SSS). This completes a search for periodic variable stars within the 30,000 square degrees of the sky covered by the Catalina Surveys. The current analysis covers 81 million sources with declinations between -20 and -75 degrees with median magnitudes in the range 11<V<19.5. We find approximately 34,000 new periodic variable stars in addition to the ~9,000 RR Lyrae that we previously discovered in SSS data. This brings the total number of periodic variables identified in Catalina data to ~110,000. The new SSS periodic variable stars mainly consist of eclipsing binaries, RR Lyrae, LPVs, RS CVn stars, {delta} Scutis and Anomalous Cepheids. By cross-matching these variable stars with those from prior surveys, we find that ~90% of the sources are new discoveries and recover ~95% of the known periodic variables in the survey region. For the known sources, we find excellent agreement between our catalogue and prior values of luminosity, period and amplitude. However, we find many variable stars that had previously been misclassified. Examining the distribution of RR Lyrae, we find a population associated with the Large Magellanic Cloud (LMC) that extends more than 20 degrees from its center confirming recent evidence for the existence of a very extended stellar halo in the LMC. By combining SSS photometry with Dark Energy Survey data, we identify additional LMC halo RR Lyrae, thus confirming the significance of the population.
1075. C star population in NGC 6822
ID:
ivo://CDS.VizieR/J/AJ/123/832
Title:
C star population in NGC 6822
Short Name:
J/AJ/123/832
Date:
21 Oct 2021
Publisher:
CDS
Description:
Using the CFH12K camera, we apply the four-band photometric technique to identify 904 carbon stars in an area 28'x42' centered on NGC 6822. A few C stars outside of this area were also discovered with the Las Campanas Swope Telescope. The NGC 6822 survey employs two sets of observations obtained by rather different telescopes and with different procedures: the Swope Telescope on Las Campanas was used in 1999 October to secure images of NGC 6822 in Kron-Cousins R_KC_, CN (810nm), and TiO (770nm) filters. The 2048x2048 SITe No. 1 CCD yields a field of view of 23.7'x23.7'; NGC 6822 was also observed with the CFH12K at the beginning of one night in 2000 September. The camera consists of a 12Kx8K pixel mosaic covering a field of 42'x28', with each pixel corresponding to 0.206". Images were obtained through Mould I and R filters and through the CN and TiO filters. The NGC 6822 C star population has <I>=19.26 leading to an <M_I_>=-4.70, value essentially identical to the mean magnitude obtained for the C stars in IC 1613. Contrary to stars highlighting the optical image of NGC 6822, C stars are seen at large radial distances and trace a huge, slightly elliptical halo, which does not coincide with the huge H I cloud surrounding NGC 6822. The previously unknown stellar component of NGC 6822 has a exponential scale length of 3.0+/-0.1' and can be traced to 5 scale lengths. The C/M ratio of NGC 6822 is evaluated to be 1.0+/-0.2.
1076. C star population in outer disk of M31
ID:
ivo://CDS.VizieR/J/A+A/436/91
Title:
C star population in outer disk of M31
Short Name:
J/A+A/436/91
Date:
21 Oct 2021
Publisher:
CDS
Description:
We employ the CFHT Megacam camera to survey ~1{deg}^2^ of the southern outer disc of M31, a region which includes the area where Battinelli et al. (2003, Cat. <J/AJ/125/1298>) have identified nearly one thousand C stars. In the outer M31 region not previously surveyed, we identify 361 new C star candidates, having similar photometric properties to the known ones, and confirm the slight decrease in the luminosity of C stars with galactocentric distances. We show that the Sloan g', r', i' filters are a viable approach, comparable to (CN-TiO), to identify C stars. We find that the (g'-r') colours of cool C stars can be so red that prohibitively long g' exposures are needed to acquire faint extragalactic C stars. This makes the Sloan filters a less promising approach to extend a C star survey to several Mpc. Our uniform large field survey detects the edge of M31 disk at ~35kpc. The intermediate-age population, represented by C stars, extends further to ~40kpc.
1077. C star population in outer disk of M31
ID:
ivo://CDS.VizieR/J/AJ/125/1298
Title:
C star population in outer disk of M31
Short Name:
J/AJ/125/1298
Date:
21 Oct 2021
Publisher:
CDS
Description:
We employ the CFH12K mosaic to identify carbon stars, using the R, I, CN, and TiO photometric technique, in a 2240 arcmin2 area, ranging from 17 to 30kpc of the southwest disk of M31, barely reaching the edge of the observed H I disk. We found 945 C stars with <I_0_>=19.94mag and {sigma}=0.47. The surface density of C stars along the major axis of M31 follows an exponential profile with a scale length of 4.85+/-0.35kpc, in agreement with adopted values for the scale length of the disk population. Our survey partially overlaps with the recently discovered G1 density enhancement by Ferguson et al. We confirm that no AGB star excess is detectable in the surveyed part of the clump. The C/M ratio, along the major axis, is derived over a distance range of 7kpc. The strong C/M gradient seen contrasts with results of previous studies of the C stars in M31.
1078. C stars in IC 1613
ID:
ivo://CDS.VizieR/J/AJ/119/2780
Title:
C stars in IC 1613
Short Name:
J/AJ/119/2780
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present results of a multifilter survey of the whole Magellanic-type galaxy IC 1613. Narrowband CN and TiO filters are used to identify carbon stars among red giants. We have identified 195 carbon stars, extending up to 15' from the center of the galaxy. We present well-calibrated R and I magnitudes for all stars. The large field surveyed allows a reliable foreground estimate of M stars, leading to a C/M ratio of 0.64, when giants as early as M0 are counted. Analysis of the photometric properties of the C star population reveals a narrow M_I_ distribution with a mean M_I_ of -4.69mag, with a dispersion of +/-0.28. IC 1613 has, for its absolute magnitude, a normal number of C stars.
1079. C stars in Pegasus, DDO 210 and Tucana
ID:
ivo://CDS.VizieR/J/AJ/120/1801
Title:
C stars in Pegasus, DDO 210 and Tucana
Short Name:
J/AJ/120/1801
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the latest results of our ongoing four-filter photometric survey of C stars in Local Group dwarf irregular galaxies. Observations of the two low-luminosity dwarf irregular galaxies, Pegasus and DDO 210, revealed 40 and three C stars, respectively, assuming that the reddening of Pegasus is negligible. No C stars were identified in Tucana. Our observations permit the estimation of the color-magnitude diagram contamination by foreground M dwarfs thus yielding reliable C/M ratios. Our R and I photometry of the C stars cannot be used to solve the extinction controversy toward Pegasus. The three C stars in DDO 210 are quite bright when compared with C star populations in other dwarf galaxies. A larger, fainter population in that galaxy seems improbable, however. The statistics of C stars currently on hand for dwarf galaxies show a well-defined trend with the absolute magnitude of dwarf galaxies.
1080. C stars in SMC
ID:
ivo://CDS.VizieR/J/A+AS/97/603
Title:
C stars in SMC
Short Name:
J/A+AS/97/603
Date:
21 Oct 2021
Publisher:
CDS
Description:
Accurate positions and charts for 1707 carbon stars in the Small Magellanic Cloud identified on GRISM plates are presented. The catalog provides data on magnitudes, colors, and carbon-abundance measurements and can be used for selecting carbon stars with special characteristics.