- ID:
- ivo://CDS.VizieR/J/AJ/138/1508
- Title:
- 2MASS large-amplitude variable stars
- Short Name:
- J/AJ/138/1508
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a catalog of variable stars in the near-infrared wavelength detected with overlapping regions of the Two Micron All Sky Survey public images, and discuss their properties. The investigated region is in the direction of the Galactic center (-30{deg}<~l<~20, |b|<~20), which covers the entire bulge. We have detected 136 variable stars, of which six are already known and 118 are distributed in the |b|<5{deg} region. Additionally, 84 variable stars have optical counterparts in Digitized Sky Survey images. The three diagrams (color-magnitude, light variance, and color-color diagrams) indicate that most of the detected variable stars should be large-amplitude and long-period variables such as Mira variables or OH/IR stars. The number density distribution of the detected variable stars implies that they trace the bar structure of the Galactic bulge.
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Search Results
- ID:
- ivo://CDS.VizieR/J/A+A/403/943
- Title:
- Mass-loss rates of galactic AGB stars
- Short Name:
- J/A+A/403/943
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We are using the 2002 data-release from the Japanese space experiment IRTS to investigate the spatial distribution of galactic mass-losing (>2x10^-8_M_{sun}_/yr) AGB stars and the relative contribution of C-rich and O-rich ones to the replenishment of the ISM. Our sample contains 126 C-rich and 563 O-rich sources which are sorted on the basis of the molecular bands observed in the range 1.4-4.0{mu}m, and for which we estimate distances and mass loss rates from near-infrared photometry (K and L'). There is a clear dependence on galactocentric distance, with O-rich sources outnumbering C-rich ones for {tau}_GC_<8kpc, and the reverse for {tau}_GC_>10kpc. The contribution to the replenishment of the ISM by O-rich AGB stars relative to C-rich ones follows the same trend. Although they are rare (~10% in our sample), sources with 10^-6^M_{sun}_/yr<dM/dt<10^-5^M_{sun}_/yr dominate the replenishment of the ISM by contributing to ~50% of the total of the complete sample. We find 2 carbon stars at more than 1kpc from the Galactic Plane, that probably belong to the halo of our Galaxy.
- ID:
- ivo://CDS.VizieR/J/ApJ/476/311
- Title:
- 2MASS M-dwarf discoveries
- Short Name:
- J/ApJ/476/311
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have obtained follow-up spectroscopy of eight late dwarf candidates discovered in a 105deg^2^ area observed with the 2MASS (2 Micron All-Sky Survey) Prototype Camera during test runs between 1992 and 1994. These objects were chosen because of their red infrared colors (e.g., J-Ks>=1.10) and/or red OIR colors (e.g., R-Ks>=6.00). All eight are late M dwarfs, six of which have spectral types later than van Biesbroeck 8 (type M7 V). Despite the fact that we have only followed up a fraction of the reddest sources discovered, the number of known M dwarfs of type M7 and cooler has been increased by 30%. Extrapolation of these results alone shows that over 2000 dwarfs of similar spectral type and with Ks<=14.0 will be imaged by 2MASS over the entire sky. One of these new discoveries is astonishingly cool and has a tentative type of >=M10V. This dwarf, one of the least luminous objects yet discovered, could itself be a high-mass brown dwarf, thus providing another empirical data point in a regime where few such objects are now recognized. Only the substellar suspect GD 165 B and the bona fide brown dwarf GL 229 B, both discovered as companions to known stars, are cooler. Thus, this 2MASS discovery becomes the coolest isolated object so far identified.
- ID:
- ivo://CDS.VizieR/J/other/NewA/11.27
- Title:
- 2MASS observation of BL Lac objects
- Short Name:
- J/other/NewA/11.
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The 2MASS observations of known BL Lac objects are presented in this paper. The 2MASS associations for 511 BL Lac objects are identified. From the 2MASS near infrared two-color diagram it is seen that majority (about 70%) of objects are lying alone with or very close to the power law distribution implying that there is no need to invoke any significant radiation mechanism additional to a power law continuum for those sources. However, many sources (about 30%) are still located very close to the blackbody distribution indicative of the possible contributions from the host galaxies. In addition, the average spectral index derived for the near infrared region is 0.66+/-0.34 that is rather smaller than that from the previous results indicative of the possible influence from the host galaxies and/or from the lack or weakness of the radio emissions from most sources newly discovered by recent X-ray missions.
- ID:
- ivo://CDS.VizieR/J/other/NewA/16.503
- Title:
- 2MASS observation of BL Lac objects II.
- Short Name:
- J/other/NewA/16.
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In this paper, we have searched for the Two Micron All Sky Survey (2MASS, Cat. II/246) counterparts of 1434 BL Lacs. 833 of 1434 BL Lacs (58%) have spatially coincident 2MASS counterparts. Fermi-detected BL Lacs (FBLs) have a much higher 2MASS detection rate than non-Fermi-detected BL Lacs (non-FBLs) (95% vs 49%).
- ID:
- ivo://CDS.VizieR/J/MNRAS/357/732
- Title:
- 2MASS photometry of galactic planetary nebulae
- Short Name:
- J/MNRAS/357/732
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The recently published 2MASS all-sky infrared survey (<II/246>) includes JHKs photometry of over 300 million sources. It also provides sizes and aspect ratios for the ~0.55 per cent of objects that appear in the extended-source catalogue. Although most of these detections correspond to galaxies, stars, H II regions, young stellar objects, reflection nebulae and so forth, a number of them also appear to correspond to galactic planetary nebulae (PNe). We have used this survey to determine the near-infrared properties of some 325 known galactic PNe.
- ID:
- ivo://CDS.VizieR/J/ApJ/867/12
- Title:
- Mass-richness relations for X-ray and SZE clusters
- Short Name:
- J/ApJ/867/12
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We study the mass-richness relation of 116 spectroscopically confirmed massive clusters at 0.4<z<2 by mining the Spitzer archive. We homogeneously measure the richness at 4.5um for our cluster sample within a fixed aperture of 2' radius and above a fixed brightness threshold, making appropriate corrections for both background galaxies and foreground stars. We have two subsamples, those which have (a) literature X-ray luminosities and (b) literature Sunyaev-Zel'dovich effect masses. For the X-ray subsample we re-derive masses adopting the most recent calibrations. We then calibrate an empirical mass-richness relation for the combined sample spanning more than one decade in cluster mass and find the associated uncertainties in mass at fixed richness to be +/-0.25dex. We study the dependence of the scatter of this relation with galaxy concentration, defined as the ratio between richness measured within an aperture radius of 1' and 2'. We find that at fixed aperture radius the scatter increases for clusters with higher concentrations. We study the dependence of our richness estimates with depth of the 4.5um imaging data and find that reaching a depth of at least [4.5]=21(AB)mag is sufficient to derive reasonable mass estimates. We discuss the possible extension of our method to the mid-infrared WISE All Sky Survey data and the application of our results to the Euclid mission. This technique makes richness-based cluster mass estimates available for large samples of clusters at very low observational cost.
- ID:
- ivo://CDS.VizieR/J/AJ/126/2421
- Title:
- 2MASS-Selected sample of ultracool dwarfs
- Short Name:
- J/AJ/126/2421
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the initial results of our effort to create a statistically robust, volume-limited sample of ultracool dwarfs from the Two Micron All Sky Survey Second Incremental Data Release (<II/241>). We are engaged in a multifaceted search for nearby late-type objects, and this is the first installment of our search using purely photometric selection. The goal of this work is a determination of the low-mass star and brown dwarf luminosity function in the infrared. Here we outline the construction of the sample, dubbed 2MU2, and present our first results, including the discovery of 186 M7-L6 dwarfs, 47 of which are likely to be within 20pc of the Sun. These results represent 66% of the ultracool candidates in our sample yet constitute a 127% increase in the number of ultracool dwarfs known within the volume searched (covering 40% of the sky out to 20pc). In addition, we have identified 10 M4-M6.5 objects that are likely to be within 20pc (or within 1{sigma}). Finally, based on these initial data, we present a preliminary luminosity function and discuss several interesting features of the partial sample presented here. Once our sample is complete, we will use our measured luminosity function to constrain the mass function of low-mass stars and brown dwarfs.
- ID:
- ivo://CDS.VizieR/J/MNRAS/475/343
- Title:
- 2MASS, WISE, and SuperCOSMOS clusters of galaxies
- Short Name:
- J/MNRAS/475/343
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We identify 47600 clusters of galaxies from photometric data of Two Micron All Sky Survey (2MASS), Wide-field Infrared Survey Explorer (WISE), and SuperCOSMOS, among which 26125 clusters are recognized for the first time and mostly in the sky outside the Sloan Digital Sky Survey (SDSS) area. About 90 per cent of massive clusters of M_500_>3x10^14^M_{sun}_ in the redshift range of 0.025<z<0.3 have been detected from such survey data, and the detection rate drops down to 50 per cent for clusters with a mass of M_500_~1x10^14^M_{sun}_. Monte Carlo simulations show that the false detection rate for the whole cluster sample is less than 5 per cent. By cross-matching with ROSAT and XMM-Newton sources, we get 779 new X-ray cluster candidates which have X-ray counterparts within a projected offset of 0.2Mpc.
- ID:
- ivo://CDS.VizieR/II/281
- Title:
- 2MASS 6X Point Source Working Database / Catalog
- Short Name:
- II/281
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A special set of observations that utilized exposure times six times longer than the main 2MASS survey measurements were conducted in the final year of 2MASS observatory operations. The 2MASS "6x" observations achieved sensitivities ~1 mag deeper than the main 2MASS survey, and covered approximately 590 deg2 of sky in 30 discrete regions. The 2MASS 6x Point Source Working Databases (6x-PSWDB and 6x-XSWDB) contain all detections extracted from the raw 6x imaging data during pipeline data reduction. The 6x WDB entries include reliable detections of astrophysical sources, as well as spurious detections of noise excursions, image artifacts and transient events such as meteor trails, cosmic rays and hot pixels. In addition, the WDBs may contain multiple, independent detections of objects scanned more than once during the 6x observations. The 2MASS 6x Point Source Catalogs (6x-PSC and 6x-XSC) is a subset of extractions in the 6x-PSWDB that have been identified to be high reliability source detections, with only one measurement of sources detected multiple times for uniformity.
