- ID:
- ivo://nasa.heasarc/einopslgal
- Title:
- Einstein Survey of Optically Selected Galaxies
- Short Name:
- Einstein/OGal
- Date:
- 27 Sep 2024
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The Einstein Survey of Optically Selected Galaxies contains the results of a complete Einstein Imaging Proportional Counter (IPC) X-ray survey of optically-selected galaxies from the Shapley-Ames (S-A) Catalog (CDS Catalog <VII/112>), the Uppsala General Catalog (UGC, <a href="https://cdsarc.cds.unistra.fr/ftp/cats/VII/26">CDS Catalog <VII/26></a>) and the European Southern Observatory (ESO) Catalog (<a href="https://cdsarc.cds.unistra.fr/ftp/cats/VII/115">CDS Catalog <VII/115></a>). Well-defined optical criteria were used to select the galaxies, and X-ray fluxes were measured at the optically-defined positions. The result is a comprehensive list of X-ray detection and upper limit measurements for 1018 galaxies. Of these, 827 galaxies have either independent distance estimates or radial velocities. Associated optical, redshift, and distance data have been assembled for these galaxies, and their distances come from a combination of directly predicted distances and those predicted from the Faber-Burstein Great Attractor/Virgocentric infall model. The accuracy of the X-ray fluxes has been checked in three different ways; all are consistent with the derived X-ray fluxes being of <= 0.1 dex accuracy. In particular, there is agreement with previously published X-ray fluxes for galaxies in common with a 1991 study by Roberts et al. (1991ApJS...75..751R) and a 1992 study by Fabbiano et al. (1992ApJS...80..531F, also available at the HEASARC as a database table called EINGALCAT). This database was created at the HEASARC in May 2002 based on the ADC/<a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/ApJS/111/163">CDS Catalog J/ApJS/111/163</a> and is derived from Tables 5, 6, 7, 12, 13, and 14 of the published paper. This is a service provided by NASA HEASARC .
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- ID:
- ivo://CDS.VizieR/J/ApJ/325/798
- Title:
- Einstein survey of stars in the Hyades
- Short Name:
- J/ApJ/325/798
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The paper reports the results of an extensive X-ray study of the Hyades region and improves on previous studies by using refined X-ray source detection algorithms and the complete set of Einstein Observatory IPC exposures covering the Hyades cluster region (a total of 63 1 x 1 deg images). Maximum likelihood integral X-ray luminosity functions were computed for the Hyades stars for given color index (B-V) ranges. The present results agree substantially with a previous survey about the ubiquity of the stellar activity in the Hyades cluster, especially among solar-type stars. The result of Stern et al. (1981ApJ...249..647S) that stellar X-ray emission is dependent on stellar age is confirmed.
- ID:
- ivo://CDS.VizieR/J/ApJ/437/361
- Title:
- Einstein survey of the Orion nebula region
- Short Name:
- J/ApJ/437/361
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have analyzed archival Einstein Observatory images of a roughly 4.5 square degree region centered on the Orion Nebula. In all, 245 distinct X-ray sources have been detected in six High Resolution Imager (HRI) and 17 Imaging Proportional Counter (IPC) observations. An optical database of over 2700 stars has been assembled to search for candidate counterparts to the X-ray sources. Roughly half the X-ray sources are identified with a single Orion Nebula cluster member. The 10 main-sequence O6-B5 cluster stars detected in Orion have X-ray activity levels comparable to field O and B stars. X-ray emission has also been detected in the direction of four main-sequence late-B and early-A type stars. Since the mechanisms producing X-rays in late-type coronae and early-type winds cannot operate in the late-B and early-A type atmospheres, we argue that the observed X-rays, with L_X_~3x10^30^ergs/s, are probably produced in the coronae of unseen late-type binary companions. Over 100 X-ray sources have been associated with late-type pre-main sequence stars.
- ID:
- ivo://nasa.heasarc/twosigma
- Title:
- Einstein Two-Sigma Catalog
- Short Name:
- Einstein/ETS
- Date:
- 27 Sep 2024
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The X-ray sources from observations made with the Einstein Observatory (HEAO-2) Imaging Proportional Counter (IPC) that have intensities of 2-sigma or more above the background are compiled in this catalog. This catalog covers more sky at fainter flux levels than the Einstein Medium Sensitivity Survey. Fields with diffuse emission sources such as bright Abell clusters of galaxies and supernova remnants were excluded. Thus, data within 10 degrees of the galactic plane as well as fields within the boundaries of the Magellanic Clouds were excluded. Regions crowded with galactic sources such as the Orion and Pleiades fiels were also excluded. Excluding redundant fields, this catalog covers 1850 sq. degrees of the sky. The generation of the Einstein Two-Sigma Catalog was described in detail by Moran et al. (1996). Please read this article carefully to ensure responsible use of the Catalog. Detailed scientific and technical questions on the contents and methodology of this catalog should be addressed to the first author, Ed Moran (edhed@igpp.llnl.gov). In particular, it should be noted that, by design, this catalog contains a significant number of spurious sources: only 28%, or about 13,000 sources, out of the 46,000 source in the 2-sigma catalog are `real` astrophysical sources, with the remainder of the sources being spurious ones. Moran et al. show in their paper that performing cross-correlations of 2-sigma sources with other catalogs is an effective way of selecting sources in this catalog that are probably real. This is a service provided by NASA HEASARC .
- ID:
- ivo://CDS.VizieR/J/ApJS/111/163
- Title:
- Einstein X-ray survey of galaxies. I.
- Short Name:
- J/ApJS/111/163
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of a complete Einstein imaging proportional counter X-ray survey of optically-selected galaxies from the Shapley-Ames Catalog (Cat. <VII/112>), the Uppsala General Catalog (Cat. <VII/26>) and the European Southern Observatory Catalog (Cat. <VII/115>). Well-defined optical criteria are used to select the galaxies, and X-ray fluxes are measured at the optically-defined positions. The result is a comprehensive list of X-ray detection and upper limit measurements for 1018 galaxies. Of these, 827 have either independent distance estimates or radial velocities. Associated optical, redshift, and distance data have been assembled for these galaxies, and their distances come from a combination of directly predicted distances and those predicted from the Faber-Burstein Great Attractor/Virgocentric infall model. The accuracy of the X-ray fluxes has been checked in three different ways; all are consistent with the derived X-ray fluxes being of <=0.1 dex accuracy. In particular, there is agreement with previously published X-ray fluxes for galaxies in common with a 1991 study by Roberts et al. (1991ApJS...75..751R) and a 1992 study by Fabbiano et al. (1992ApJS...80..531F).The data presented here will be used in further studies to characterize the X-ray output of galaxies of various morphological types and thus to enable the determination of the major sources contributing to the X-ray emission from galaxies.
- ID:
- ivo://CDS.VizieR/J/A+A/456/881
- Title:
- EIS: infrared deep public survey
- Short Name:
- J/A+A/456/881
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This paper is part of the series presenting the final results obtained by the ESO Imaging Survey (EIS) project. It presents new J and Ks data obtained from observations conducted at the ESO 3.5m New Technology Telescope (NTT) using the SOFI camera. These data were taken as part of the Deep Public Survey (DPS) carried out by the ESO Imaging Survey program, significantly extending the earlier optical/infrared EIS-DEEP survey presented in a previous paper of this series. The DPS-IR survey comprises two observing strategies: shallow Ks observations providing nearly full coverage of pointings with complementary multi-band (in general UBVRI) optical data obtained using ESO's wide-field imager (WFI) and deeper J and Ks observations of the central parts of these fields. Currently, the DPS-IR survey provides a coverage of roughly 2.1 square degrees (~300 SOFI pointings) in Ks with 0.63 square degrees to fainter magnitudes and also covered in J, over three independent regions of the sky. The goal of the present paper is to briefly describe the observations, the data reduction procedures, and to present the final survey products which include fully calibrated pixel-maps and catalogs extracted from them. The astrometric solution with an estimated accuracy of <0.15" is based on the USNO catalog and limited only by the accuracy of the reference catalog. The final stacked images presented here number 89 and 272, in J and Ks, respectively, the latter reflecting the larger surveyed area. The J and Ks images were taken with a median seeing of 0.7" and 0.8". The images reach a median 5 sigma limiting magnitude of J_AB~23.06 as measured within an aperture of 2", while the corresponding limiting magnitude in Ks_AB is ~21.41 and ~22.16mag for the shallow and deep strategies. Although some spatial variation due to varying observing conditions is observed, overall the observed limiting magnitudes are consistent with those originally proposed. The quality of the data has been assessed by comparing the measured magnitude of sources at the bright end directly with those reported by the 2MASS survey and at the faint end by comparing the counts of galaxies and stars with those of other surveys to comparable depth and to model predictions. The final science-grade catalogs together with the astrometrically and photometrically calibrated co-added images are available at CDS.
- ID:
- ivo://CDS.VizieR/J/A+A/452/119
- Title:
- EIS: infrared observations of CDF-S and HDF-S
- Short Name:
- J/A+A/452/119
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This paper presents infrared data obtained from observations carried out at the ESO 3.5m New Technology Telescope (NTT) of the Hubble Deep Field South (HDF-S) and the Chandra Deep Field South (CDF-S). These data were taken as part of the ESO Imaging Survey (EIS) program, a public survey conducted by ESO to promote follow-up observations with the VLT. In the HDF-S field the infrared observations cover an area of ~53 square arcmin, encompassing the HST WFPC2 and STIS fields, in the JHKs passbands. The seeing measured in the final stacked images ranges from 0.79" to 1.22" and the median limiting magnitudes (AB system, 2" aperture, 5sigma detection limit) are J_AB~23.0, H_AB~22.8 and K_AB~23.0mag. Less complete data are also available in JKs for the adjacent HST NICMOS field. For CDF-S, the infrared observations cover a total area of ~100 square arcmin, reaching median limiting magnitudes (as defined above) of J_AB~23.6 and K_AB~22.7mag. For one CDF-S field H-band data are also available. This paper describes the observations and presents the results of new reductions carried out entirely through the un-supervised, high-throughput EIS Data Reduction System and its associated EIS/MVM C++-based image processing library developed, over the past 5 years, by the EIS project and now publicly available. The paper also presents source catalogs extracted from the final co-added images which are used to evaluate the scientific quality of the survey products, and hence the performance of the software. This is done comparing the results obtained in the present work with those obtained by other authors from independent data and/or reductions carried out with different software packages and techniques.
- ID:
- ivo://CDS.VizieR/J/A+A/462/553
- Title:
- EIS: optical deep public survey
- Short Name:
- J/A+A/462/553
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This paper presents new five passbands (UBVRI) optical wide-field imaging data accumulated as part of the DEEP Public Survey (DPS) carried out as a public survey by the ESO Imaging Survey (EIS) project. Out of the 3 square degrees originally proposed, the survey covers 2.75 square degrees, in at least one band (normally R), and 1.00 square degrees in five passbands. The median seeing, as measured in the final stacked images, is 0.97", ranging from 0.75" to 2.0". The median limiting magnitudes (AB system, 2" aperture, 5{sigma} detection limit) are U_AB_=25.65, B_AB_=25.54, V_AB_=25.18, R_AB_=24.8 and I_AB_=24.12mag, consistent with those proposed in the original survey design. The paper describes the observations and data reduction using the EIS Data Reduction System and its associated EIS/MVM library. The quality of the individual images were inspected, bad images discarded and the remaining used to produce final image stacks in each passband, from which sources have been extracted. Finally, the scientific quality of these final images and associated catalogs was assessed qualitatively by visual inspection and quantitatively by comparison of statistical measures derived from these data with those of other authors as well as model predictions, and from direct comparison with the results obtained from the reduction of the same dataset using an independent (hands-on) software system. Finally to illustrate one application of this survey, the results of a preliminary effort to identify sub-mJy radio sources are reported. To the limiting magnitude reached in the R and I passbands the success rate ranges from 66 to 81% (depending on the fields).
- ID:
- ivo://CDS.VizieR/J/A+A/620/A87
- Title:
- Ejection processes in NGC 2264
- Short Name:
- J/A+A/620/A87
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of a study of forbidden [OI]6300{AA} emission line profiles in classical T Tauri stars in the young, open cluster NGC 2264. We separate each of these profiles into up to four features via Gaussian decomposition: narrow and broad low-velocity components and blue- and redshifted high-velocity components. We study the luminosities and kinematic properties of these components along with known stellar and accretion parameters, in order to investigate their origins.
- ID:
- ivo://CDS.VizieR/J/MNRAS/343/293
- Title:
- ELAIS deep X-ray survey. I.
- Short Name:
- J/MNRAS/343/293
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present an analysis of two deep (75ks) Chandra observations of the European Large Area Infrared Space Observatory (ISO) Survey (ELAIS) fields N1 and N2 as the first results from the ELAIS deep X-ray survey. This survey is being conducted in well-studied regions with extensive multiwavelength coverage. Here we present the Chandra source catalogues along with an analysis of source counts, hardness ratios and optical classifications. A total of 233 X-ray point sources are detected in addition to two soft extended sources, which are found to be associated with galaxy clusters. An overdensity of sources is found in N1 with 30 per cent more sources than N2, which we attribute to large-scale structure. A similar variance is seen between other deep Chandra surveys. The source count statistics reveal an increasing fraction of hard sources at fainter fluxes. The number of galaxy-like counterparts also increases dramatically towards fainter fluxes, consistent with the emergence of a large population of obscured sources.