- ID:
- ivo://CDS.VizieR/J/MNRAS/380/281
- Title:
- Faint galactic satellites spectroscopic survey
- Short Name:
- J/MNRAS/380/281
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of a spectroscopic survey of the recently discovered faint Milky Way satellites Bootes, Ursa Major I, Ursa Major II and Willman 1 (Wil1). Using the DEep Imaging Multi-Object Spectrograph mounted on the Keck II telescope, we have obtained samples that contain from ~15 to ~85 probable members of these satellites for which we derive radial velocities precise to a few km/s down to i~21-22. About half of these stars are observed with a high enough signal-to-noise ratio to estimate their metallicity to within +/-0.2dex. The characteristics of all the observed stars are made available, along with those of the Canes Venatici I dwarf galaxy that have been analysed in a companion paper.
Number of results to display per page
Search Results
- ID:
- ivo://CDS.VizieR/VII/208
- Title:
- Faint Galaxies at the North Galactic Pole
- Short Name:
- VII/208
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The North Galactic Pole Canada-France-Hawaii Telescope Catalogue of faint galaxies is made available. We provide positions, photometric and structural parameters for more than 50000 galaxies. The J and F magnitudes were obtained from IIIaJ and IIIaF CFHT prime focus plates respectively. This catalogue have been used in many studies of faint galaxy properties. Galaxy counts, colour distributions and clustering properties of faint galaxies have been obtained with these data. Statistical properties of stars have been studied as well. For details refer to Infante and Pritchet (1992ApJS...83..237I), Pritchet and Infante (1992ApJ...399L..35P), Infante (1994A&A...282..353), Infante (1994A&AS..107..413I) and Infante and Pritchet (1995ApJ...439..565I). The magnitude errors range from: +/-0.3mag at J=24 to less than +/-0.1 at J=20 +/-0.3mag at F=23 to less than +/-0.1 at F=19 The rms uncertainty in the zero points is 0.022 (J) and 0.038 (F)
- ID:
- ivo://CDS.VizieR/J/MNRAS/297/885
- Title:
- Faint galaxies KIc photometry
- Short Name:
- J/MNRAS/297/885
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The excess number of blue galaxies at faint magnitudes is a subject of much controversy. Recent Hubble Space Telescope results have revealed a plethora of galaxies with peculiar morphologies tentatively identified as the evolving population. We report the results of optical spectroscopy and near-infrared photometry of a sample of faint HST galaxies from the Medium Deep Survey to ascertain the physical properties of the faint morphological populations. We find four principal results. First, the population of objects classified as 'peculiar' are intrinsically luminous in the optical (M_B_~-19). Secondly these systems tend to be strong sources of [OII] line luminosity. Thirdly the optical-infrared colours of the faint population (a) confirm the presence of a population of compact blue galaxies and (b) show the stellar populations of irregular/peculiar galaxies encompass a wide range in age. Finally a surface-brightness comparison with the local galaxy sample of Freiz et al. (1996AJ....111..174F) shows that these objects are not of anomalously low surface brightness, rather we find that all morphological classes have evolved to a higher surface brightness at higher redshifts (z>0.3).
- ID:
- ivo://CDS.VizieR/J/MNRAS/235/827
- Title:
- Faint galaxy redshift survey
- Short Name:
- J/MNRAS/235/827
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Using the fibre optic coupler at the Anglo-Australian Observatory, we have completed a new faint galaxy redshift survey. Intermediate dispersion spectra with resolution ~4{AA} have been gathered for over 200 field galaxies selected in apparent magnitude slices between 20.0<b_J_<21.5mag in five high-latitude fields. Redshift completeness is 85% and the mean redshift agrees well from field to field.
- ID:
- ivo://CDS.VizieR/J/MNRAS/352/1245
- Title:
- Faint 1.4GHz radio sources in 2dFGRS
- Short Name:
- J/MNRAS/352/1245
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have used the Australia Telescope Compact Array (ATCA) to search for faint radio sources in a ~3deg^2^ region of sky covered by the 2dF Galaxy Redshift Survey (2dFGRS, Cat. <VII/226>). Over the region surveyed, the 1{sigma} noise level at 1.4GHz ranges from 20Jy to 1mJy. The survey region includes 365 2dFGRS galaxies, of which 316 have good-quality spectra (176 early-type galaxies or active galactic nuclei, and 140 star-forming galaxies). The fraction of 2dFGRS galaxies detected as radio sources in our survey rises from ~4% at a 3{sigma} detection limit of 0.3mJy to 12% at 75{mu}Jy, with roughly equal numbers of star-forming galaxies and active galactic nuclei (AGNs) being detected.
- ID:
- ivo://CDS.VizieR/J/A+A/522/A79
- Title:
- Faint, high-Galactic-latitude red clump stars
- Short Name:
- J/A+A/522/A79
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- With this survey we aim to derive accurate, multi-epoch radial velocities and atmospheric parameters (Teff, logg, [M/H] and V_rot_sini) of a large sample of carefully selected red clump (RC) stars located over a great circle at high Galactic latitudes. We acquired data of the program stars of high signal-to-noise ratio and high resolution with the Asiago Echelle spectrograph. We obtained radial velocities by applying cross-correlation and atmospheric parameters via chi2 fitting to a synthetic spectral library. Extensive tests were carried out by re-observing with the same instrument a large number of standard stars taken from a variety of sources in literature.
- ID:
- ivo://CDS.VizieR/J/A+A/527/A40
- Title:
- Faint, high-Galactic-latitude red clump stars
- Short Name:
- J/A+A/527/A40
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The goal of our survey is to provide accurate and multi-epoch radial velocities, atmospheric parameters (Teff, logg and [M/H]), distances, and space velocities of faint red clump (RC) stars. We recorded high signal-to-noise (S/N>=200) spectra of RC stars over the 4750-5950{AA} range at a resolving power 5500. The target stars are distributed across the great circle of the celestial equator. Radial velocities were obtained via cross-correlation with IAU radial velocity standards. Atmospheric parameters were derived via {chi}^2^ fit to a synthetic spectral library. A large number of RC stars from other surveys were re-observed to check the consistency of our results and the absence of offsets and trends.
- ID:
- ivo://CDS.VizieR/J/AJ/124/1651
- Title:
- Faint high-latitude carbon stars SDSS photometry
- Short Name:
- J/AJ/124/1651
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the discovery of 39 faint high-latitude carbon stars (FHLCs) from Sloan Digital Sky Survey (SDSS) commissioning data. The objects, each selected photometrically and verified spectroscopically, range over 16.6<r*<20.0 and show a diversity of temperatures as judged by both colors and NaD line strengths. Although a handful of these stars were previously known, these objects are, in general, too faint and too warm to be effectively identified in other modern surveys such as the Two Micron All Sky Survey, nor are their red/near-IR colors particularly distinctive. We present proper-motion measures for each object, indicating that the sample is a mixture of extremely distant (greater than 100kpc) halo giant stars, useful for constraining halo dynamics, and members of the recently recognized exotic class of very nearby dwarf carbon (dC) stars.
- ID:
- ivo://CDS.VizieR/J/AJ/127/2838
- Title:
- Faint high-latitude carbon stars SDSS photometry
- Short Name:
- J/AJ/127/2838
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A search of more than 3000deg^2^ of high-latitude sky by the Sloan Digital Sky Survey has yielded 251 faint high-latitude carbon stars (FHLCs), the large majority previously uncatalogued. We present homogeneous spectroscopy, photometry, and astrometry for the sample. The objects lie in the 15.6<r<20.8 range and exhibit a wide variety of apparent photospheric temperatures, ranging from spectral types near M to as early as F. Proper-motion measurements for 222 of the objects show that at least 50%, and quite probably more than 60%, of these objects are actually low-luminosity dwarf carbon (dC) stars, in agreement with a variety of recent, more limited investigations that show that such objects are the numerically dominant type of star with C_2_ in the spectrum. This SDSS homogeneous sample of ~110 dC stars now constitutes 90% of all known carbon dwarfs and will grow by another factor of 2-3 by the completion of the survey. As the spectra of the dC and the faint halo giant C stars are very similar (at least at spectral resolution of 10^3^), despite a difference of 10mag in luminosity, it is imperative that simple luminosity discriminants other than proper motion be developed. We use our enlarged sample of FHLCs to examine a variety of possible luminosity criteria, including many previously suggested, and find that, with certain important caveats, JHK photometry may segregate dwarfs and giants.
- ID:
- ivo://nasa.heasarc/first
- Title:
- Faint Images of the Radio Sky at Twenty cm (FIRST)
- Short Name:
- FIRST
- Date:
- 27 Sep 2024
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This catalog comprises the Faint Images of the Radio Sky at Twenty cm (FIRST) Survey. The FIRST survey began in 1993, and covers the north and south Galactic caps. The present 14Dec17 version is derived from the 1993 through 2011 observations. The catalog covers a total of about 10,575 square degrees of sky (8,444 square degrees in the north Galactic cap and 2,131 square degrees in the south Galactic cap). See the coverage maps at <a href="http://sundog.stsci.edu/first/catalogs/readme_14dec17.html#coverage">http://sundog.stsci.edu/first/catalogs/readme_14dec17.html#coverage</a> for more details of the area covered. Both the northern and southern areas were chosen to coincide approximately with the area covered by the Sloan Digital Sky Survey (SDSS). The catalog is identical to the previous version of the catalog (14Mar04) except that it has more accurate data on which sources are not covered by the SDSS DR10 catalog. Approximately 1000 sources that were indicated as covered by DR10 in the previous version are now correctly marked as not covered. The source list, radio fluxes, etc., are all the same as the 14Mar04 version. In this version of the catalog, images taken in the the new EVLA configuration have been re-reduced using shallower CLEAN thresholds in order to reduce the "CLEAN bias" in those images. Also, the EVLA images are not co-added with older VLA images to avoid problems resulting from the different frequencies and noise properties of the configurations. That leads to small gaps in the sky coverage at boundaries between the EVLA and VLA regions. As a result, the area covered by this release of the catalog is about 60 square degrees smaller than the earlier release of the catalog (13Jun05), and the total number of sources is reduced by nearly 25,000. The previous version of the catalog does have sources in the overlap regions, but their flux densities are considered unreliable due to calibration errors. The flux densities should be more accurate in this catalog, biases are smaller, and the incidence of spurious sources is also reduced. Over most of the survey area, the detection limit is 1 mJy. A region along the equatorial strip (RA = 21.3 to 3.3 hrs, Dec = -1 to 1 deg) has a deeper detection threshold because two epochs of observation were combined. The typical detection threshold in this region is 0.75 mJy. There are approximately 4,500 sources below the 1 mJy threshold used for most previous versions of the catalog. The format of this catalog is the same as releases since 13Jun05 but differs from earlier versions of the catalog. It contains two parameters which give information on the epoch of observation for each source (called mean_epoch and rms_epoch in this HEASARC version) which are described below. The P(S) parameter (called sidelobe_prob herein), which indicates the probability that the source is a sidelobe, replaces the previous binary sidelobe flag column. The parameters sdss_matches, sdss_first_offset, sdss_imag, sdss_class, twomass_matches, twomass_first_offset and twomass_kmag give information on counterparts to the FIRST source in the SDSS DR10 catalog and the 2MASS catalog, respectively. Other catalog parameters are common with FIRST catalog releases extending back over the past decade. The co-added images are available online: see the FIRST page at <a href="http://sundog.stsci.edu/first/images.html">http://sundog.stsci.edu/first/images.html</a> for details. The source catalog presented here is derived from the images. Data for the FIRST survey were collected in all VLA B-configurations from Spring 1993 through Spring 2004. For all data collected for the FIRST project, the raw u-v visibility data are placed in the VLA public archive on the day they are taken, and are available for use without restriction. Additional data in the southern Galactic cap were acquired in Spring 2009 and Spring 2011. The VLA was in a hybrid condition in 2009, with some new EVLA receivers and some old VLA receivers. The characteristics of those images are slightly different from the older data, but for most purposes they should be equivalent. In 2011 the EVLA receivers were available with an early version of the new EVLA data system, so there are a number of differences from the old data: <pre> Date Frequencies Bandpass Integration Before 2011 1365, 1435 MHz 2x7 3-MHz channels 180 seconds 2011 1335, 1730 MHz 2x64 2-MHz channels 60 seconds </pre> Note particularly the frequency difference between the new and older data. The new data are in co-added fields with names ending with 'S' (and later letters in the alphabet) and are found entirely in the south Galactic cap. This table was last updated by the HEASARC in May 2015 based on the file: <a href="http://sundog.stsci.edu/first/catalogs/catalog_14dec17.bin.gz">http://sundog.stsci.edu/first/catalogs/catalog_14dec17.bin.gz</a> which contains the 17 December 2014 version of the FIRST Source Catalog. Some of the values for the name parameter in the HEASARC's implementation of this table were corrected in April 2018. This is a service provided by NASA HEASARC .