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791. RMS survey. 6cm observations of YSOs
ID:
ivo://CDS.VizieR/J/A+A/501/539
Title:
RMS survey. 6cm observations of YSOs
Short Name:
J/A+A/501/539
Date:
21 Oct 2021
Publisher:
CDS
Description:
The Red MSX Source (RMS) survey is an ongoing multi-wavelength observational programme designed to return a large, well-selected sample of massive young stellar objects (MYSOs). We have identified ~2000 MYSO candidates located throughout the Galaxy by comparing the colours of MSX and 2MASS point sources to those of known MYSOs. The aim of these follow-up observations is to identify other objects with similar colours such as ultra compact (UC) HII regions, evolved stars and planetary nebulae (PNe) and distinguish between genuine MYSOs and nearby low-mass YSOs. To identify the populations of UCHII regions and PNe within the sample and examine their Galactic distribution. We have conducted high resolution radio continuum observations at 6cm towards 659 MYSO candidates in the northern hemisphere (10{deg}<l<250{deg}) using the Very Large Array (VLA). These observations have a spatial resolution of ~1-2" and typical image rms noise values of ~0.22mJy - sensitive enough to detect a HII region powered by B0.5 star at the far side of the Galaxy. In addition to these targeted observations we present archival data towards a further 315 RMS sources extracted from a previous VLA survey of the inner Galaxy.
792. RM Synthesis of 33 sources around M31
ID:
ivo://CDS.VizieR/J/A+A/559/A27
Title:
RM Synthesis of 33 sources around M31
Short Name:
J/A+A/559/A27
Date:
21 Oct 2021
Publisher:
CDS
Description:
Low-frequency radio continuum observations are best suited to search for radio halos of inclined galaxies. Polarization measurements at low frequencies allow the detection of small Faraday rotation measures caused by regular magnetic fields in galaxies and in the foreground of the Milky Way. The detection of low-frequency polarized emission from a spiral galaxy such as M31 allows us to assess the degree of Faraday depolarization, which can be compared with models of the magnetized interstellar medium.
793. ROGUE. I. SDSS galaxies with FIRST
ID:
ivo://CDS.VizieR/J/ApJS/247/53
Title:
ROGUE. I. SDSS galaxies with FIRST
Short Name:
J/ApJS/247/53
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the catalog of Radio sources associated with Optical Galaxies and having Unresolved or Extended morphologies I (ROGUE I), consisting of 32616 spectroscopically selected galaxies. It is the largest handmade catalog of this kind, obtained by cross-matching galaxies from the Sloan Digital Sky Survey (SDSS) Data Release 7 and radio sources from both the First Images of Radio Sky at Twenty Centimetre (FIRST) survey and the NRAO Very Large Array Sky Survey, without imposing a limit on the radio flux densities. The catalog provides a visual classification of radio and optical morphologies of galaxies presenting a FIRST core within 3" of the optical position. The radio morphological classification is performed by examining the radio-optical overlays of linear sizes equal to 1Mpc at the source distance, while the 120" image snapshots from the SDSS database are used for optical classification. The results of our search are as follows: (i) single-component unresolved and elongated radio sources constitute the major group in the ROGUE I catalog (~90%), and ~8% exhibit extended morphologies; (ii) samples of 269, 730, and 115 Fanaroff-Riley (FR) type I, II, and hybrid galaxies, respectively, are presented; (iii) we report 55 newly discovered giant/possible giant, 16 double-double, 9 X-shaped, and 25 Z-shaped radio sources; (iv) on the optical front, most galaxies have elliptical morphologies (~62%) while spirals form the second major category (~17%) followed by distorted (~12%) and lenticular (~7%) morphologies; and (v) division between the FR I and the FR II sources in the radio-optical luminosity plane is blurred, in tune with recent studies.
794. ROSAT active galaxies identifications
ID:
ivo://CDS.VizieR/J/A+AS/122/235
Title:
ROSAT active galaxies identifications
Short Name:
J/A+AS/122/235
Date:
21 Oct 2021
Publisher:
CDS
Description:
Table 2 gives the 5 GHz high resolution radio source properties for the 1861 Rosat-GreenBank (RGB) sources for which subarcsecond positions and core radio flux densities were obtained. After submission of this paper, we discovered a possible systematic position error in a very small subset of sources. In particular, the sources RGB J0131+005, RGB J0139+178, RGB J0143+129, RGB J0157+235A, RGB J0232+202, RGB J0233+024A, RGB J0243+171, RGB J0256+035, RGB J0303+059, RGB J0308+104, RGB J0312+243A, RGB J0312+242C, and RGB J0314+063 were all observed in our "c" epoch VLA runs and show large systematic offsets with respect to sources found in the NVSS survey. We re-examined these sources and found the position reported in the tables is accurate given our data, but that the noise on these fields before any CLEANing is abnormally high. We thank Dr. Alastair Edge for pointing out this discrepancy. Table 3 gives the 5 GHz radio source properties for the 436 Rosat-Green Bank (RGB) sources for which only low resolution data were obtained. Table 4 gives the 83 Rosat-Green Bank (RGB) sources for which no radio source greater than 5 sigma was observed in the follow-up VLA observations. These catalogs consist of radio- and X-ray-loud AGN selected from a correlation of the 1987 Green Bank radio catalog and the Rosat All-Sky Survey.
795. ROSAT AGN content
ID:
ivo://CDS.VizieR/J/A+AS/109/147
Title:
ROSAT AGN content
Short Name:
J/A+AS/109/147
Date:
21 Oct 2021
Publisher:
CDS
Description:
The cross-correlation of the source list from the ROSAT All-Sky Survey with the 5 GHz Green Bank survey yields a list of 2127 objects. About two thirds of them are optically unidentified. The majority of the objects with known optical counterparts are quasars and radio galaxies, most of them detected in X-rays for the first time. In this paper we present a list of the previously optically identified objects with their main characteristics and discuss their general (bulk) properties. We find strong correlations between luminosities in the radio, optical, and X-ray bands which differ for quasars and radio galaxies.
796. ROSAT-FIRST AGN correlation
ID:
ivo://CDS.VizieR/J/A+A/356/445
Title:
ROSAT-FIRST AGN correlation
Short Name:
J/A+A/356/445
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the results of a correlation of the ROSAT All-Sky Survey with the April 1997 release of the VLA 20cm FIRST (Cat. <VIII/59>) catalogue. We focus our analysis on the 843 X-ray sources which have unique radio counterparts. The majority of these objects (84%) have optical counterparts on the POSS 1 plates. Approximately 30% have been previously classified and we obtain new spectroscopic classifications for 85 sources by comparison with the ongoing FIRST Bright Quasar Survey and 106 additional sources from our own new spectroscopic data. Approximately 51% of the sources are presently classified, and the majority of the unclassified objects are optically faint. The newly classified sources are generally radio weak, exhibiting properties intermediate with previous samples of radio- and X-ray-selected AGN. This also holds for the subsample of 71 BL Lacs which includes many intermediate objects. The 146 quasars show no evidence for a bimodal distribution in their radio-loudness parameter, indicating that the supposed division between radio-quiet and radio-loud AGN may not be real. The X-ray and radio luminosities are correlated over two decades in radio luminosity, spanning the radio-loud and radio-quiet regimes, with radio-quiet quasars showing a linear correlation between the two luminosities. Many of the sources show peculiar or unusual properties which call for more detailed follow-up observations. We also give the X-ray and radio data for the 518 X-ray sources for which more than one radio object is found. Because of the difficulties inherent in identifying optical counterparts to these complex sources, we do not consider these data in the current analysis.
797. ROSAT Galactic Plane Survey observations
ID:
ivo://CDS.VizieR/J/A+AS/122/201
Title:
ROSAT Galactic Plane Survey observations
Short Name:
J/A+AS/122/201
Date:
21 Oct 2021
Publisher:
CDS
Description:
The analysis of the part of the ROSAT all-sky survey covering the galactic plane is the scope of a dedicated project called the ROSAT Galactic Plane Survey. In order to statistically understand the nature of the =~14000 sources discovered by ROSAT at |b|<=20{deg}, a number of sample areas have been chosen for follow-up optical identification. In this paper we present the X-ray and optical material gathered in a region located in the Cygnus constellation, centered at l=90{deg}, b=0{deg} and covering an area of 64.5deg^2^. A total of 95 and 128 sources are detected with a maximum likelihood larger than 10 and 8 respectively. With a typical survey exposure time of the order of 700 to 900 s the flux completeness level is =~0.02cts/s corresponding to =~2x10^-13^erg/cm^2^/s. The position of the sample area allows to investigate the soft X-ray content of a rather typical region of the galactic plane. In this paper we describe the details of the observational procedures and data reduction. For each ROSAT source we list the main X-ray characteristics together with those of the proposed optical identification. When appropriate, we also show optical spectra and finding charts. The full analysis and discussion of these data are presented in a companion paper (Motch et al. 1997, Cat. <J/A+A/318/111>).
798. ROSAT North Ecliptic Pole Survey
ID:
ivo://CDS.VizieR/J/ApJS/149/29
Title:
ROSAT North Ecliptic Pole Survey
Short Name:
J/ApJS/149/29
Date:
21 Oct 2021
Publisher:
CDS
Description:
The X-ray data around the North Ecliptic Pole (NEP) of the ROSAT All Sky Survey have been used to construct a contiguous area survey consisting of a sample of 445 individual X-ray sources above a flux of ~2x10^-14^erg/cm^2^/s in the 0.5-2.0keV energy band. The NEP survey is centered at RA=18:00 (2000) DE=+66:33 and covers a region of 80.7deg^2^ at a moderate Galactic latitude of b=29.8{deg}. Hence, the NEP survey is as deep and covers a comparable solid angle to the ROSAT serendipitous surveys but is also contiguous. We have identified 99.6% of the sources and determined redshifts for the extragalactic objects. In this paper we present the optical identifications of the NEP catalog of X-ray sources including basic X-ray data and properties of the sources. We also describe with some detail the optical identification procedure. The classification of the optical counterparts to the NEP sources is very similar to that of previous surveys, in particular the Einstein Extended Medium Sensitivity Survey (EMSS). The main constituents of the catalog are active galactic nuclei (AGNs) (~49%), either type 1 or type 2 according to the broadness of their permitted emission lines. Stellar counterparts are the second most common identification class (~34%). Clusters and groups of galaxies comprise 14%, and BL Lacertae objects 2%. One non-AGN galaxy and one planetary nebula have also been found. The NEP catalog of X-ray sources is a homogeneous sample of astronomical objects featuring complete optical identification.
799. Rosat North Ecliptic survey stellar population
ID:
ivo://CDS.VizieR/J/A+A/461/977
Title:
Rosat North Ecliptic survey stellar population
Short Name:
J/A+A/461/977
Date:
21 Oct 2021
Publisher:
CDS
Description:
X-ray surveys are a very efficient mean of detecting young stars and therefore allow us to study the young stellar population in the solar neighborhood and the local star formation history in the last billion of years. We want to study the young stellar population in the solar neighborhood, to constrain its spatial density and scale height as well as the recent local star formation history. We analyze the stellar content of the ROSAT North Ecliptic Pole survey, and compare the observations with the predictions derived from stellar galactic model. Since the ROSAT NEP survey is sensitive at intermediate fluxes is able to sample both the youngest stars and the intermediate age stars (younger than 10^9^years), linking the shallow and deep flux surveys already published in the literature. We confirm the existence of an excess of yellow stars in our neighborhood previously seen in shallow survey, which is likely due to a young star population not accounted for in the model. However the excellent agreement between observations and predictions of dM stars casts some doubt on the real nature of this active population.
800. ROSAT X-ray observations of M81
ID:
ivo://CDS.VizieR/J/ApJ/554/202
Title:
ROSAT X-ray observations of M81
Short Name:
J/ApJ/554/202
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present results from the analysis of deep ROSAT HRI and PSPC observations of the spiral galaxy M81. The inferred total (0.5-2keV band) luminosity of M81 is ~3x10^40^ergs/s, excluding the contribution from identified interlopers found within the D_25_ ellipse. The nucleus of the galaxy alone accounts for about 65% of this luminosity. The rest is due to 26 other X-ray sources (contributing ~10%) and to apparently diffuse emission, which is seen across much of the galactic disk and is particularly bright in the bulge region around the nucleus. Spectral analysis further gives evidence for a soft component, which can be characterized by a two-temperature optically thin plasma with temperature at ~0.15 and 0.60keV and an absorption of the galactic foreground only. These components, accounting for ~13% of the X-ray emission from the region, apparently arise in a combination of hot gas and faint discrete sources. We find interesting spatial coincidences of luminous (10^37^-10^40^ergs/s) and variable X-ray sources with shock-heated optical nebulae. Three of them are previously classified as supernova remnant candidates. The other one is far off the main body of M81 but is apparently associated with a dense H I concentration produced most likely by the tidal interactions of the galaxy with its companions. These associations suggest that such optical nebulae may be powered by outflows from luminous X-ray binaries, which are comparable to, or more luminous than, Galactic "microquasars."

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