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J/AJ/132/866        New M dwarfs in solar neighborhood          (Riaz+, 2006)

Identification of new M dwarfs in the solar neighborhood. Riaz B., Gizis J.E., Harvin J. <Astron. J., 132, 866-872 (2006)> =2006AJ....132..866R
ADC_Keywords: Stars, nearby ; Stars, M-type ; Photometry, infrared Keywords: stars: activity - stars: fundamental parameters - stars: late-type - X-rays: stars Abstract: We present the results from a spectroscopic study of 1063 nearby active M dwarfs, selected by correlating the Two Micron All Sky Survey and ROSAT catalogs. We have derived the spectral types and estimated distances for all of our stars. The spectral types range between K5 and M6. Nearly half of our stars lie within 50pc. We have measured the equivalent width of the Hα emission line. Our targets show an increase in chromospheric activity from early to midspectral types, with a peak in activity around M5. Using the count rate and hardness ratios obtained from the ROSAT catalog, we have derived the X-ray luminosities. Our stars display a "saturation-type" relation between the chromospheric and coronal activity. The relation is such that log(LX/Lbol) remains "saturated" at a value of approximately -3 for varying Hα equivalent width. We have found 568 matches in the USNO-B catalog and have derived the tangential velocities for these stars. There is a slight trend of decreasing chromospheric activity with age, such that the stars with higher vtan have lower Hα equivalent widths. The coronal emission, however, remains saturated at a value of log(LX/Lbol)~-3 for varying tangential velocities, suggesting that the coronal activity remains saturated with age. We do not find any break in the saturation-type relation at the spectral type at which stars become fully convective (∼M3.5). Most of the stars in our sample show more coronal emission than the dMe stars in the Hyades and Praesepe and have vtan<40km/s, suggesting a young population. Description: We have obtained medium-resolution infrared spectra of the stars in our sample using the Palomar 60 inch (1.5m) telescope for the northern stars and the Cerro Tololo Inter-American Observatory 1.5m telescope for the southern hemisphere stars. Data from the Palomar 60inch were obtained in 2000 October and November and in 2001 June. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table1.dat 113 1063 Observed and derived quantities of nearby M stars
See also: II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003) Byte-by-byte Description of file: table1.dat
Bytes Format Units Label Explanations
1- 16 A16 --- 2M The 2MASS identification (1) 18- 21 F4.2 --- CaH1 ? The CaH1 index 23- 26 F4.2 --- CaH2 ? The CaH2 index 28- 31 F4.2 --- CaH3 ? The CaH3 index 33- 36 F4.2 --- TiO5 The TiO5 index (bandheads at 650 and 705nm) 38- 42 F5.2 mag Jmag 2MASS J band magnitude 44- 48 F5.2 mag Hmag 2MASS H band magnitude 50- 54 F5.2 mag Kmag 2MASS K band magnitude 56- 59 A4 --- SpType MK spectral type, mainly from TiO5 index 61- 65 F5.1 0.1nm EWHa ? Hα equivalent width in Angstroms 67- 71 F5.2 [-] log(LX/Lbol) Log of the X-ray to Bolometric luminosities 73- 75 I3 km/s Vtan ? Tangential velocity 77- 80 I4 pc Dist Spectroscopic distance 82- 83 I2 pc pDist ? Distance from parallax 85-113 A29 --- OName Other name(s) of the star (2)
Note (1): Format is HHMMSSs+DDMMSS for 2MASS-I = Cat. II/241, or HHMMSSss+DDMMSSs for 2MASS-Final = Cat. II/246. Note (2): errors detected and corrected at CDS are marked (*), see the "History" section below.
History: * 08-Feb-2008: From electronic version of the journal Table 1 from erratum, 2007, AJ, 133, 1208 * 07-Jul-2009: Wrong identifications in column 'OName' corrected at CDS; errors are marked with (*) in the 'OName' column and concern: * CE 102 which was indicated 03360868+3118398 but CE 102 = 09455843-3253299 * BPS CS 22939-0062 was assigned to 2 stars 19222035-2754587 and 19222935-2754587 but BPS CS 22939-0062 = 19214521-1948136
(End) Greg Schwarz [AAS], Patricia Vannier [CDS] 08-Feb-2008
The document above follows the rules of the Standard Description for Astronomical Catalogues.From this documentation it is possible to generate f77 program to load files into arrays or line by line

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