- ID:
- ivo://CDS.VizieR/J/other/RAA/15.1182
- Title:
- M Dwarf catalog of LAMOST DR1
- Short Name:
- J/other/RAA/15.1
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a spectroscopic catalog of 93 619 M dwarfs from the first data release of the Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) general survey. During sample selection, M giant contamination was eliminated using 2MASS photometry and CaH/TiO molecular indices. For each spectrum, the spectral subtype and values are provided including radial velocity, H{alpha} equivalent width, a series of prominent molecular band indices, and the metal-sensitive parameter {zeta}, as well as distances and the space motions for high S/N objects. In addition, H{alpha} emission lines are measured to examine the magnetic activity properties of M dwarfs and 7179 active ones are found. In particular, a subsample with significant variation in magnetic activity is revealed through observations from different epochs. Finally, statistical analysis for this sample is performed, including the metallicity classification, the distribution of molecular band indices and their errors.
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Search Results
- ID:
- ivo://CDS.VizieR/J/ApJ/818/153
- Title:
- MEarth photometry: nearby M-dwarf magnitudes
- Short Name:
- J/ApJ/818/153
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The MEarth Project is a photometric survey systematically searching the smallest stars near the Sun for transiting rocky planets. Since 2008, MEarth has taken approximately two million images of 1844 stars suspected to be mid-to-late M dwarfs. We have augmented this survey by taking nightly exposures of photometric standard stars and have utilized this data to photometrically calibrate the MEarth system, identify photometric nights, and obtain an optical magnitude with 1.5% precision for each M dwarf system. Each optical magnitude is an average over many years of data, and therefore should be largely immune to stellar variability and flaring. We combine this with trigonometric distance measurements, spectroscopic metallicity measurements, and 2MASS infrared magnitude measurements in order to derive a color-magnitude-metallicity relation across the mid-to-late M dwarf spectral sequence that can reproduce spectroscopic metallicity determinations to a precision of 0.1 dex. We release optical magnitudes and metallicity estimates for 1567 M dwarfs, many of which did not have an accurate determination of either prior to this work. For an additional 277 stars without a trigonometric parallax, we provide an estimate of the distance, assuming solar neighborhood metallicity. We find that the median metallicity for a volume-limited sample of stars within 20pc of the Sun is [Fe/H]=-0.03+/-0.008, and that 29/565 of these stars have a metallicity of [Fe/H]=-0.5 or lower, similar to the low-metallicity distribution of nearby G dwarfs. When combined with the results of ongoing and future planet surveys targeting these objects, the metallicity estimates presented here will be important for assessing the significance of any putative planet-metallicity correlation.
- ID:
- ivo://CDS.VizieR/J/ApJ/857/51
- Title:
- Measuring dark energy properties with PS1 SNe. II.
- Short Name:
- J/ApJ/857/51
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We use 1169 Pan-STARRS supernovae (SNe) and 195 low-z (z<0.1) SNe Ia to measure cosmological parameters. Though most Pan-STARRS SNe lack spectroscopic classifications, in a previous paper we demonstrated that photometrically classified SNe can be used to infer unbiased cosmological parameters by using a Bayesian methodology that marginalizes over core-collapse (CC) SN contamination. Our sample contains nearly twice as many SNe as the largest previous SN Ia compilation. Combining SNe with cosmic microwave background (CMB) constraints from Planck, we measure the dark energy equation-of-state parameter w to be -0.989+/-0.057 (stat+sys). If w evolves with redshift as w(a)=w0+wa(1-a), we find w0=-0.912+/-0.149 and wa=-0.513+/-0.826. These results are consistent with cosmological parameters from the Joint Light-curve Analysis and the Pantheon sample. We try four different photometric classification priors for Pan-STARRS SNe and two alternate ways of modeling CC SN contamination, finding that no variant gives a w differing by more than 2% from the baseline measurement. The systematic uncertainty on w due to marginalizing over CC SN contamination, {sigma}_w_^CC^=0.012, is the third-smallest source of systematic uncertainty in this work. We find limited (1.6{sigma}) evidence for evolution of the SN color-luminosity relation with redshift, a possible systematic that could constitute a significant uncertainty in future high-z analyses. Our data provide one of the best current constraints on w, demonstrating that samples with ~5% CC SN contamination can give competitive cosmological constraints when the contaminating distribution is marginalized over in a Bayesian framework.
- ID:
- ivo://CDS.VizieR/J/A+AS/134/115
- Title:
- Medicina 6.7GHz methanol masers survey
- Short Name:
- J/A+AS/134/115
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- File table2 contains the name of the sources and their coordinates (1950) observed, but not detected, with the Medicina Radiotelescope at 6.7GHz in 1995, March. Source are associated with one or more type of phenomena typical of star forming regions (see note 1 for code description). The number of non detected sources is 387.
1095. MegaZ-LRG catalogue
- ID:
- ivo://CDS.VizieR/J/MNRAS/375/68
- Title:
- MegaZ-LRG catalogue
- Short Name:
- J/MNRAS/375/68
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We describe the construction of MegaZ-LRG, a photometric redshift catalogue of over one million luminous red galaxies (LRGs) in the redshift range 0.4<z<0.7 with limiting magnitude i<20. The catalogue is selected from the imaging data of the Sloan Digital Sky Survey (SDSS) Data Release 4. The 2dF-SDSS LRG and Quasar (2SLAQ) spectroscopic redshift catalogue of 13000 intermediate-redshift LRGs provides a photometric redshift training set, allowing use of ANNZ, a neural network-based photometric-redshift estimator. The rms photometric redshift accuracy obtained for an evaluation set selected from the 2SLAQ sample is z=0.049 averaged over all galaxies, and z=0.040 for a brighter subsample (i<19.0). The catalogue is expected to contain ~5 per cent stellar contamination. The ANNZ code is used to compute a refined star/galaxy probability based on a range of photometric parameters; this allows the contamination fraction to be reduced to 2 per cent with negligible loss of genuine galaxies. The MegaZ-LRG catalogue is publicly available on the World Wide Web from http://www.2slaq.info .
- ID:
- ivo://nasa.heasarc/skyview/mellinger
- Title:
- Mellinger All Sky Mosaic: Red
- Short Name:
- MELLINGER
- Date:
- 25 Apr 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This all sky mosaic was created by Axel Mellinger and is used in <i>SkyView</i> with his permission. A fuller description is available at the <a href="https://www.milkywaysky.com/">survey website</a>. <p> Between October 2007 and August 2009 a digital all-sky mosaic was assembled from more than 3000 individual CCD frames. Using an SBIG STL-11000 camera, 70 fields (each covering 40x27 degrees) were imaged from dark-sky locations in South Africa, Texas and Michigan. In order to increase the dynamic range beyond the 16 bits of the camera's analog-to-digital converter (of which approximately 12 bits provide data above the noise leve) three different exposure times (240s, 15s and 0.5 s) were used. Five frames were taken for each exposure time and filter setting. The frames were photometrically calibrated using standard catalog stars and sky background data from the Pioneer 10 and 11 space probes. the panorama has an image scale of 36"/pixel and a limiting magnitude of approximately 14. The survey has an 18 bit dynamic range. <p> The processing of these data used a custom data pipeline built using IRAF, Source Extractor and SWarp. <p> The data used here were converted to three independent RGB color planes of 8 bits each and provided to SkyView as a single 36000x18000x3 Cartesian projection cube. To allow users to efficiently sample data in a region of the sky, this cube was broken up into 2100x2100 pixel regions with a 50 pixel overlap between adjacent images. Tiles at the poles were 2100x2050. <p> In <i>SkyView</i> each color plane comprises a survey. The individual planes may be sampled as surveys independently as Mellinger-R, Mellinger-G and Mellinger-B. The color mosaics can be regenerated by creating an RGB image of all three surveys. Since <i>SkyView</i> may stretch the intensity values within each color, linear scaling and a minimum of 0 and maximum of 255 should be specified to keep the original intensity scalings. <p> The full spatial resolution data is used for images of less than 30 degrees on a side. If a user requests a larger region, data are sampled from a lower resolution 3600x1800x3 data cube. Please contact the survey author if you need to use the higher resolution data for larger regions. The Mellinger survey is only available in <i>SkyView</i> through the website. SkyView-in-a-Jar cannot access the underlying data. Provenance: Axel Mellinger. This is a service of NASA HEASARC.
- ID:
- ivo://CDS.VizieR/J/ApJ/877/13
- Title:
- Member stars of the GD-1 tidal stream
- Short Name:
- J/ApJ/877/13
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- With the photometric data from the SDSS survey, the spectroscopic data from the SDSS/SEGUE and the LAMOST surveys, and the astrometric data from the Gaia DR2, we have identified 67 highly probable member stars of the GD-1 cold stellar stream spread along almost its entire length (i.e., from 126{deg} to 203{deg} in R.A.). With the accurate spectroscopic (i.e., metallicity and line-of-sight velocity) and astrometric (i.e., proper motions) information, the position-velocity diagrams, i.e., {phi}_1_-{mu}_{alpha}_, {phi}_1_-{mu}_{delta}_, and {phi}_1_-v_gsr_, of the GD-1 stream are well mapped. The stream has an average metallicity [Fe/H]=-1.96. The rich information of member stars of the stream now available allow one not only to model its origin, but also to place strong constraints on the mass distribution and the gravitational potential of the Milky Way.
- ID:
- ivo://CDS.VizieR/J/ApJS/237/36
- Title:
- Merging dwarf galaxies in the local universe
- Short Name:
- J/ApJS/237/36
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the largest publicly available catalog of interacting dwarf galaxies. It includes 177 nearby merging dwarf galaxies of stellar mass M*<10^10^M_{sun}_ and redshifts z<0.02. These galaxies are selected by visual inspection of publicly available archival imaging from two wide-field optical surveys (SDSS-III and the Legacy Survey), and they possess low-surface-brightness features that are likely the result of an interaction between dwarf galaxies. We list UV and optical photometric data that we use to estimate stellar masses and star formation rates. So far, the study of interacting dwarf galaxies has largely been done on an individual basis, and lacks a sufficiently large catalog to give statistics on the properties of interacting dwarf galaxies, and their role in the evolution of low-mass galaxies. We expect that this public catalog can be used as a reference sample to investigate the effects of the tidal interaction on the evolution of star formation, and the morphology/structure of dwarf galaxies. Our sample is overwhelmingly dominated by star-forming galaxies, and they are generally found significantly below the red sequence in the color-magnitude relation. The number of early-type galaxies is only 3 out of 177. We classify them, according to observed low-surface-brightness features, into various categories including shells, stellar streams, loops, antennae, or simply interacting. We find that dwarf-dwarf interactions tend to prefer the low-density environment. Only 41 out of the 177 candidate dwarf-dwarf interaction systems have giant neighbors within a sky-projected distance of 700kpc and a line-of-sight radial velocity range +/-700km/s, and compared to the LMC-SMC, they are generally located at much larger sky-projected distances from their nearest giant neighbors.
- ID:
- ivo://CDS.VizieR/J/A+A/600/A28
- Title:
- Merging galaxies in Pan-STARR
- Short Name:
- J/A+A/600/A28
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We studied the r'-, z'-, and y'-band images of merging galaxies from the observations of the Panoramic Survey Telescope & Rapid Response System (Pan-STARRS). The merging galaxies were selected from our merging catalog that was created by checking the images of the Red-Sequence Cluster Survey 2 from the observations of the Canada France Hawaii Telescope By using the homomorphic-aperture, we determined the photometric results of these merging systems. To obtain accurate photometry, we calibrated the Pan-STARRS r'-, z'-, and y'-band data to match the results of Sloan Digital Sky Survey Data Release 9. We also investigated the stellar masses of the merging galaxies by comparing the Wide-field Infrared Survey Explorer 3.4um emission with the calibrated y'-band data. We present a catalog of the r'-, z'-, and y'-band photometric results for 4698 merging galaxies. For extended sources, our results suggest that the homomorphic-aperture method can obtain more reasonable results than the Desktop Virtual Observatory photometry. We derived new relations between the Pan-STARRS y'-band luminosities and the stellar masses of the merging galaxies. Our results show that the stellar masses of the merging galaxies range from 10^8^ to 10^13^M_{sun}_; some of the dry mergers could be as massive as 10^13^M_{sun}_.
- ID:
- ivo://CDS.VizieR/J/AJ/127/1883
- Title:
- Merging galaxies in SDSS EDR
- Short Name:
- J/AJ/127/1883
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a new catalog of merging galaxies obtained through an automated systematic search routine. The 1479 new pairs of merging galaxies were found in ~462 square degrees of the Sloan Digital Sky Survey Early Data Release (SDSS EDR, Cat. <J/AJ/123/567>) photometric data, and the pair catalog is complete for galaxies in the magnitude range 16.0<=g*<=20. The selection algorithm, implementing a variation on the original Karachentsev criteria, proved to be very efficient and fast. Merging galaxies were selected such that the intergalaxy separations were less than the sum of the component galaxies' radii. We discuss the characteristics of the sample in terms of completeness, pair separation, and the Holmberg effect. We also present an on-line atlas of images for the SDSS EDR pairs obtained using the corrected frames from the SDSS EDR database. The atlas images also include the relevant data for each pair member. This catalog will be useful for conducting studies of the general characteristics of merging galaxies, their environments, and their component galaxies. The redshifts for a subset of the interacting and merging galaxies and the distribution of angular sizes for these systems indicate the SDSS provides a much deeper sample than almost any other wide-area catalog to date.
