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4071. M33 SNR candidates properties
ID:
ivo://CDS.VizieR/J/ApJ/793/134
Title:
M33 SNR candidates properties
Short Name:
J/ApJ/793/134
Date:
21 Oct 2021
Publisher:
CDS
Description:
Narrowband images covering strong emission lines are efficient for surveying supernova remnants (SNRs) in nearby galaxies. Using the narrowband images provided by the Local Group Galaxy Survey, we searched for SNRs in M33. Culling the objects with enhanced [S II]/H{alpha} and round morphology in the continuum-subtracted H{alpha} and [S II] images, we produced a list of 199 sources. Among them, 79 are previously unknown. Their progenitor and morphology types were classified. A majority of the sample (170 objects) are likely remnants of core-collapse supernovae (SNe), and 29 are remnants of Type Ia SNe. The cumulative size distribution of these objects is found to be similar to that of the M31 remnants derived in a similar way. We obtain a power-law slope, {alpha}=2.38+/-0.05. Thus, a majority of the sources are considered to be in the Sedov-Taylor phase, consistent with previous findings. The histogram of the emission-line ratio ([S II]/H{alpha}) of the remnants has two concentrations at [S II]/H{alpha} ~0.55 and ~0.8, as in M31. Interestingly, L_X_(and L_20 cm_) of the compact center-bright objects are correlated with their optical luminosity. The remnants with X-ray emission have brighter optical surface brightnesses and smaller diameters than those without X-ray emission.
4072. M81 star cluster candidates
ID:
ivo://CDS.VizieR/J/AJ/139/1413
Title:
M81 star cluster candidates
Short Name:
J/AJ/139/1413
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present a catalog of extended objects in the vicinity of M81 based on a set of 24 Hubble Space Telescope Advanced Camera for Surveys Wide Field Camera F814W (I-band) images. We have found 233 good globular cluster (GC) candidates; 92 candidate HII regions, OB associations, or diffuse open clusters; 489 probable background galaxies; and 1719 unclassified objects. We have color data from ground-based g- and r-band MMT Megacam images for 79 galaxies, 125 GC candidates, 7 HII regions, and 184 unclassified objects. The color-color diagram of GC candidates shows that most fall into the range 0.25<g-r<1.25 and 0.5<r-I<1.25, similar to the color range of Milky Way GCs. Unclassified objects are often blue, suggesting that many of them are likely to be HII regions and open clusters, although a few galaxies and GCs may be among them.
4073. 346 M31 star clusters and their parameters
ID:
ivo://CDS.VizieR/J/A+A/645/A115
Title:
346 M31 star clusters and their parameters
Short Name:
J/A+A/645/A115
Date:
21 Oct 2021
Publisher:
CDS
Description:
Determining the metallicities and ages of M31 clusters is fundamental to the study of the formation and evolution of M31 itself. The Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) has carried out a systematic spectroscopic campaign of clusters and candidates in M31. We constructed a catalogue of 346 M31 clusters observed by LAMOST. By combining the information of the LAMOST spectra and the multi-band photometry, we developed a new algorithm to estimate the metallicities and ages of these clusters. We distinguish young clusters from old using random forest classifiers based on a empirical training data set selected from the literature. Ages of young clusters are derived from the spectral energy distribution fits of their multi-band photometric measurements. Their metallicities are estimated by fitting their observed spectral principal components extracted from the LAMOST spectra with those from the young metal-rich single stellar population (SSP) models. For old clusters we built non-parameter random forest models between the spectral principal components and/or multi-band colours and the parameters of the clusters based on a training data set constructed from the SSP models. The ages and metallicities of the old clusters are then estimated by fitting their observed spectral principal components extracted from the LAMOST spectra and multi-band colours from the photometric measurements with the resultant random forest models. We derived parameters of 53 young and 293 old clusters in our catalogue. Our resultant parameters are in good agreement with those from the literature. The ages of ~30 catalogued clusters and metallicities of ~40 sources are derived for the first time.
4074. M3 stars CCD photometry
ID:
ivo://CDS.VizieR/J/A+A/320/757
Title:
M3 stars CCD photometry
Short Name:
J/A+A/320/757
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present BVI CCD photometry for more than 10,000 stars in the innermost region (0.3'<r<~4') of the globular cluster M 3. When added to the previous photographic photometry by Buonanno et al. (1994A&A...290...69B) reaching as far as r~7', this results in an homogeneous data-set including about 19,000 stars measured in this cluster, which can be now regarded as one of the main templates for stellar population studies.
4075. M-subdwarf research. I. LAMOST DR4 spectra obs.
ID:
ivo://CDS.VizieR/J/ApJS/240/31
Title:
M-subdwarf research. I. LAMOST DR4 spectra obs.
Short Name:
J/ApJS/240/31
Date:
21 Oct 2021
Publisher:
CDS
Description:
We propose a revision of the system developed by Lepine+ (2007ApJ...669.1235L) for spectroscopic M-subdwarf classification. Based on an analysis of subdwarf spectra and templates from Savcheva+ (2014ApJ...794..145S), we show that the CaH1 feature originally proposed by Gizis (1997, J/AJ/113/806) is important in selecting reliable cool subdwarf spectra. This index should be used in combination with the [TiO5, CaH2+CaH3] relation provided by Lepine+ to avoid misclassification results. In the new system, the dwarf-subdwarf separators are first derived from a sample of more than 80000 M dwarfs and a "labeled" subdwarf subsample, and these objects are all visually identified from their optical spectra. Based on these two samples, we refit the initial [TiO5, CaH1] relation and propose a new [CaOH, CaH1] relation supplementing the [TiO5, CaH1] relation to reduce the impact of uncertainty in flux calibration on classification accuracy. In addition, we recalibrate the {zeta}TiO/CaH parameter defined in Lepine+ to enable its successful application to Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) spectra. Using this new system, we select candidates from LAMOST Data Release 4 and finally identify a set of 2791 new M-subdwarf stars, covering the spectral sequence from type M0 to M7. This sample contains a large number of objects located at low Galactic latitudes, especially in the Galactic anti-center direction, expanding beyond previously published halo- and thick disk-dominated samples. Besides, we detect magnetic activity in 141 objects. We present a catalog for this M-subdwarf sample, including radial velocities, spectral indices and errors, and activity flags, with a compilation of external data (photometric and Gaia Data Release 2 astrometric parameters).
4076. M-Subdwarfs
ID:
ivo://CDS.VizieR/J/AJ/113/806
Title:
M-Subdwarfs
Short Name:
J/AJ/113/806
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present a spectroscopic classification system for M-dwarfs and M-subdwarfs based on quantitative measures of TiO and CaH features in the region 6200 - 7400 Angstroms. Our sample of cool stars covers the range from solar metallicity stars to the most extreme subdwarfs known. Using synthetic spectra computed by Allard and Hauschildt (1995), we derive metallicities for the stars. Stars are classified as dwarfs (M V), subdwarfs (sdM), or extreme subdwarfs (esdM). These classifications correspond to [m/H] = 0.0, -1.2, and -2.0 respectively. Our metallicity scale agrees with theoretical HR diagrams and HST globular cluster measurements. We discuss some nearby subdwarfs of particular interest in light of our metallicity scale. We include photometry compiled from the literature.
4077. MSX and 2MASS cross-correlation in LMC
ID:
ivo://CDS.VizieR/J/AJ/122/1844
Title:
MSX and 2MASS cross-correlation in LMC
Short Name:
J/AJ/122/1844
Date:
21 Oct 2021
Publisher:
CDS
Description:
The Large Magellanic Cloud (LMC) has been observed by the Midcourse Space Experiment (MSX) in the mid-infrared and the Two Micron All Sky Survey (2MASS) in the near-infrared. We have performed a cross-correlation of the 1806 MSX catalog sources and nearly 1.4 million 2MASS catalogued point and extended sources and find 1664 matches. Using the available color information, we identify a number of stellar populations and nebulae, including main-sequence stars, giant stars, red supergiants, carbon- and oxygen-rich asymptotic giant branch (AGB) stars, planetary nebulae, H II regions, and other dusty objects likely associated with early-type stars. A total of 731 of these sources have no previous identification. We compile a listing of all objects, which includes photometry and astrometry. The 8.3{mu}m MSX sensitivity is the limiting factor for object detection: only the brighter red objects, specifically the red supergiants, AGB stars, planetary nebulae, and H II regions, are detected in the LMC. The remaining objects are likely in the Galactic foreground. The spatial distribution of the infrared LMC sources may contribute to understanding stellar formation and evolution and the overall galactic evolution. We demonstrate that a combined mid- and near-infrared photometric baseline provides a powerful means of identifying new objects in the LMC for future ground-based and space-based follow-up observations.
4078. MSX6C Infrared Point Source Catalog
ID:
ivo://CDS.VizieR/V/114
Title:
MSX6C Infrared Point Source Catalog
Short Name:
V/114
Date:
21 Oct 2021
Publisher:
CDS
Description:
Version 2.3 of the Midcourse Space Experiment (MSX) Point Source Catalog (PSC), which supersedes the version (1.2) that was released in 1999 (Cat. V/107), contains over 100,000 more sources than the previous version. The photometry is based on co-added image plates, as opposed to single-scan data, which results in improved sensitivity and hence reliability in the fluxes. Comparison with Tycho-2 positions indicates that the astrometric accuracy of the new catalog is more than 1'' better than that in Version 1.2. In addition to the Galactic plane, Areas Missed by the Infrared Astronomical Satellite (IRAS), and the Large Magellanic Cloud, which were included in the previous catalog, Version 2.3 includes data from the Small Magellanic Cloud, eight nearby galaxies, and several molecular clouds and star forming regions. The infrared instrument on MSX was named SPIRIT III; it was a 35cm clear aperture off-axis telescope with five line scanned infrared focal plane arrays of 18.3arcsec square pixels, with a high sensitivity (0.1Jy at 8.3micron). The 6 bands are B1 (4.29micron, FWHM 4.22-4.36micron), B2 (4.25micron, 4.24-4.45micron), A (8.28micron, 6.8-10.8micron), C (12.13micron, 11.1-13.2micron), D (14.65micron, 13.5-15.9micron), and E (21.34micron, 18.2-25.1micron). The MSX catalog names of the sources have been defined according to International Astronomical Union (IAU) conventions with a unique identifier combined with the position of the source. In this case, the MSX PSC V2.3 sources are named using the convention MSX6C GLLL.llll+/-BB.bbbb, where MSX6C denotes that this is MSX data run using Version 6.0 of the CONVERT software, and GLLL.llll+/-BB.bbbb gives the Galactic coordinates of the source. (Names in the minicatalogs may differ slightly from those given in Kraemer et al. 2002AJ....124.2990K, 2003AJ....126.1423K) For ease of handling, the main catalog is broken into six files: five for the Galactic plane survey, plus the primary high latitude regions (the IRAS gaps and the LMC). The supplementary catalogs are the singleton catalog, the low-reliability catalog, and minicatalogs for 19 selected regions. All catalogs have the same format. However, the minicatalogs for the galaxies (except the SMC) and Orion do not have all the fields filled in because they were solely created from the images, not from the Point Source Extractor; there are no singleton files for these regions. Also, the minicatalogs may not have singleton or low-reliability counterparts if no sources met the inclusion criteria. All told, there are a total of 45 data files.
4079. MSX5C Infrared Point Source Catalog
ID:
ivo://CDS.VizieR/V/107
Title:
MSX5C Infrared Point Source Catalog
Short Name:
V/107
Date:
21 Oct 2021
Publisher:
CDS
Description:
The principal objective of the astronomy experiments abroad the Midcourse Space Experiment (MSX) was to complete the census of the mid-infrared (4.2-25{mu}m) sky: the areas missed by the IRAS mission (about 4% of the sky was not surveyed by IRAS), and the Galactic Plane where the sensitivity of IRAS was degraded by confusion noise in the regions of high source densities or structured extended emission. The infrared instrument on MSX is named SPIRIT III; it is a 35cm clear aperture off-axis telescope with five line scanned infrared focal plane arrays of 18.3arcsec square pixels, with a high sensitivity (0.1Jy at 8.3{mu}m). The characteristics of the 6 bands B1, B2, A, C, D and E are summarized in the "Note (1)" below. The data are contained in 7 files according to the location on the sky: 5 are related to the Galactic Plane, one (non-plane) contains the IRAS gap catalog, the the lmc.dat file contains the observations of the Large Magellanic Cloud.
4080. MSX Ultraviolet Point Source Catalog
ID:
ivo://CDS.VizieR/II/269
Title:
MSX Ultraviolet Point Source Catalog
Short Name:
II/269
Date:
21 Oct 2021
Publisher:
CDS
Description:
The Midcourse Space Experiment (MSX) Ultraviolet Point Source Catalog contains 47,283 point sources from a set of 201 observations that surveyed approximately half the sky and from a set of 32 pointed observations toward specific targets. For each source, we provide position, UV magnitude and uncertainty in at least one of six filters and where possible an identification of a nearby source from the SIMBAD database. If a nearby source is identified, we include its proximity to the MSX source, and if known, the spectral type and the B and V magnitudes of the SIMBAD object. There were 11,565 matches between MSX and SIMBAD objects, and we estimate false identification to be about 3%. The limiting fluxes differ from filter to filter, and range from 10^-16^erg/s/cm2/{AA} for IUN4 to 7.8*10^-12^erg/s/cm2/{AA} for IUW3. Because of variations among the observation sets, the catalog is not complete to the limiting magnitudes for the filters. The UV instrument on MSX was named UVISI (Mill et al., 1994, Journal of Spacecraft and Rockets, 31, 900 (1994JSpRo..31..900M in ADS); Carbary et al., 1994, Applied Optics, 33, 4201 (1994ApOpt..33.4201C in ADS)). The fields-of-view for the narrow-field and wide-field UV imagers were 1.46x1.19deg (detector pixels of 20.6"x17.5") and 13.4x9.2deg (detector pixels of 3.12'x2.27'), respectively. Four filters were used with the narrow-field imager (IUN) with effective wavelengths centered at 2480{AA} (IUN3), 2310{AA} (IUN4), 2230{AA} (IUN5), and 2930{AA} (IUN6). Two filters were used with the wide-field imager (IUW) and centered at 1320{AA} (IUW3) and 1560{AA} (IUW6). Two data files are available for the MSX UV Point Source Catalog: the calibration data file and the catalog data file.