- ID:
- ivo://CDS.VizieR/J/MNRAS/398/1129
- Title:
- Central galaxies in groups and clusters
- Short Name:
- J/MNRAS/398/1129
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Using a statistically representative sample of 911 central galaxies (CENs) from the Sloan Digital Sky Survey (SDSS) Data Release 4 group catalogue, we study how the structure (shape and size) of the first rank (by stellar mass) group and cluster members depends on (1) galaxy stellar mass (M_star_), (2) the global environment defined by the dark matter halo mass (M_halo_) of the host group and (3) the local environment defined by their special halocentric position. We quantify the structure of SDSS galaxies with a galfit-based pipeline that fits two-dimensional Sersic models to the r-band image data. Through tests with simulated and real galaxy images, we demonstrate that our pipeline can recover Sersic parameters without significant bias. Moreover, to test the impact of local environment on CENs, we compare the structure of CENs with that satellite galaxies (SATs) of comparable M_star_.
Number of results to display per page
Search Results
- ID:
- ivo://CDS.VizieR/J/A+A/586/A50
- Title:
- Central Molecular Zone H2CO temperature maps
- Short Name:
- J/A+A/586/A50
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Galactic center is the closest region in which we can study star formation under extreme physical conditions like those in high-redshift galaxies. We measure the temperature of the dense gas in the Central Molecular Zone (CMZ) and examine what drives it. We have mapped the inner 300pc of the CMZ in the temperature-sensitive J=3-2 para-formaldehyde (p-H_2_CO) transitions. We use the 3_2,1_-2_2,0_/3_0,3_-2_0,2_ line ratio to determine the gas temperature in n~10^4^-10^5^cm^-3^ gas. We produce temperature maps and cubes with 30" and 1km/s resolution and publish all data in FITS form; they can be recovered from digital object identifier doi:10.7910/DVN/27601.
- ID:
- ivo://CDS.VizieR/J/PASJ/67/90
- Title:
- Central Molecular Zone in H^13^CO^+^
- Short Name:
- J/PASJ/67/90
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present results from a high-resolution wide-field imaging observation of the Central Molecular Zone (CMZ) in H^13^CO^+^ J=1-0 and SiO v=0, J=2-1 emission lines using the 45-m telescope at the Nobeyama Radio Observatory in order to depict the high-density molecular gas mass distribution and explore molecular gas affected by interstellar shocks. By using the clumpfind algorithm we identify 114 molecular clumps in the H^13^CO^+^ data cube.
- ID:
- ivo://CDS.VizieR/J/A+A/526/A6
- Title:
- Central stars of galactic planetary nebulae
- Short Name:
- J/A+A/526/A6
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- There are more than 3000 confirmed and probable known Galactic planetary nebulae (PNe), but central star spectroscopic information is available for only 13% of them. We undertook a spectroscopic survey of central stars of PNe at low resolution and compiled a large list of central stars for which information was dispersed in the literature. We present a catalogue of 492 confirmed and probable CSPN and provide a preliminary spectral classification for 45 central star of PNe. This revises previous values of the proportion of CSPN with atmospheres poor in hydrogen in at least 30% of cases and provide statistical information that allows us to infer the origin of H-poor stars. Based on data collected at the Complejo Astronomico El Leoncito (CASLEO), which is operated under agreement between the Consejo Nacional de Investigaciones Cientificas y Tecnicas de la Republica Argentina y Universidades Nacionales de La Plata, Cordoba y San Juan, Argentina.
- ID:
- ivo://CDS.VizieR/J/A+A/531/A172
- Title:
- Central stars of planetary nebulae. II.
- Short Name:
- J/A+A/531/A172
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- There are more than 3000 confirmed and probably known Galactic planetary nebulae (PNe), but central star spectroscopic information is available for only 13% of them. We have undertaken a spectroscopic survey of the central stars in PNe to identify their spectral types. We performed spectroscopic observations at low resolution with the 2-m telescope at CASLEO, Argentina. We present the spectra of 46 central stars of PNe, most of them are OB-type and emission-line stars.
- ID:
- ivo://CDS.VizieR/J/A+A/638/A103
- Title:
- Central stars of planetary nebulae in Gaia DR2
- Short Name:
- J/A+A/638/A103
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Accurate distance measurements are fundamental to the study of planetary nebulae (PNe) but they have long been elusive. The most accurate and model-independent distance measurements for galactic PNe come from the trigonometric parallaxes of their central stars, which were only available for a few tens of objects prior to the Gaia mission. The accurate identification of PN central stars (CSPNe) in the Gaia source catalogues is a critical prerequisite for leveraging the unprecedented scope and precision of the trigonometric parallaxes measured by Gaia. Our aim is to build a complete sample of PN central star detections with minimal contamination. We developed and applied an automated technique based on the likelihood ratio method to match candidate central stars in Gaia Data Release 2 (DR2) to known PNe in the Hong Kong/AAO/Strasbourg H{alpha} (HASH) PN catalogue (Parker et al. 2016, 2016JPhCS.728c2008P), taking into account the BP-RP colours of the Gaia sources as well as their positional offsets from the nebula centres. These parameter distributions for both true central stars and background sources were inferred directly from the data. We present a catalogue of over 1000 Gaia sources that our method has automatically identified as likely PN central stars. We demonstrate how the best matches enable us to trace nebula and central star evolution and to validate existing statistical distance scales, and we discuss the prospects for further refinement of the matching based on additional data. We also compare the accuracy of our catalogue to that of previous works.
- ID:
- ivo://CDS.VizieR/J/ApJ/722/L120
- Title:
- Central surface brightness of 30000 SDSS galaxies
- Short Name:
- J/ApJ/722/L120
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Disc central surface brightness for 30000 galaxies from the Sloan Digitized Sky Survey (SDSS) Data Release 7, in the r-band. Virtual Observatory methods and tools were used to define, retrieve and analyze the images for this unprecedentedly large sample classified as spiral galaxies in the LEDA catalogue. These parameters are also available for all other SDSS bands (u,g,i,z), and they can be retrieved from the Author.
- ID:
- ivo://CDS.VizieR/J/ApJ/827/L19
- Title:
- Central surface densities in SPARC disk galaxies
- Short Name:
- J/ApJ/827/L19
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We use the Spitzer Photometry and Accurate Rotation Curves (SPARC) database to study the relation between the central surface density of stars {Sigma}_*_(0) and dynamical mass {Sigma}_dyn_(0) in 135 disk galaxies (S0 to dIrr). We find that {Sigma}_dyn_(0) correlates tightly with {Sigma}_*_(0) over 4dex. This central density relation can be described by a double power law. High surface brightness galaxies are consistent with a 1:1 relation, suggesting that they are self-gravitating and baryon dominated in the inner parts. Low surface brightness (LSB) galaxies systematically deviate from the 1:1 line, indicating that the dark matter contribution progressively increases but remains tightly coupled to the stellar one. The observed scatter is small (~0.2dex) and largely driven by observational uncertainties. The residuals show no correlations with other galaxy properties like stellar mass, size, or gas fraction.
- ID:
- ivo://CDS.VizieR/J/AJ/126/1362
- Title:
- Century Survey Galactic Halo Project. I.
- Short Name:
- J/AJ/126/1362
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Century Survey Galactic Halo Project is a photometric and spectroscopic survey from which we select relatively blue stars (V-R<0.30mag) as probes of the Milky Way halo. The survey strip spans the range of Galactic latitude 35{deg}<b<88{deg}, allowing us to study the nature of populations of stars and their systematic motions as a function of Galactic latitude. One of our primary goals is to use blue horizontal-branch stars to trace potential star streams in the halo, and to test the hierarchical model for the formation of the Galaxy. In this paper we discuss spectroscopy and multipassband photometry for a sample of 764 blue stars in the Century Survey region. Our sample consists predominantly of A- and F-type stars. We describe our techniques for determination of radial velocities, effective temperatures, metallicities, and surface gravities. Based on these measurements, we derive distance estimates by comparison with a set of calibrated isochrones. We devote special attention to the classification of blue horizontal-branch stars, and compare the results obtained from the application of the techniques of Kinman et al. 1994, Cat. <J/AJ/108/1722>, Wilhelm et al. (1999, Cat. <J/AJ/117/2308>), and Clewley et al. (2002MNRAS.337...87C). We identify 55 blue horizontal-branch stars. Our large sample of stars also uncovers a number of unusual objects, including three carbon-enhanced stars, a late B-type star located 0.8kpc above the Galactic plane, and a DZ white dwarf.
2280. Cep A X-Ray sources
- ID:
- ivo://CDS.VizieR/J/ApJ/626/272
- Title:
- Cep A X-Ray sources
- Short Name:
- J/ApJ/626/272
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the discovery of X-rays from both components of Cepheus A, East and West, with the XMM-Newton observatory. HH 168 joins the ranks of other energetic Herbig-Haro objects that are sources of T>=10^6^K X-ray emission. We detect 102 X-ray sources, many presumed to be premain-sequence stars on the basis of the reddening of their optical and IR counterparts.
