J/ApJS/131/47 Gas-rich dwarfs from the POSS-II. III. (Eder+, 2000)
Gas-rich dwarfs from the PSS-II. III. H I profiles and dynamical masses.
Eder J.A., Schombert J.M.
<Astrophys. J. Suppl. Ser. 131, 47 (2000)>
=2000ApJS..131...47E 2000ApJS..131...47E
ADC_Keywords: Galaxies, radio ; H I data ; Radio lines
Keywords: galaxies: dwarf - galaxies: fundamental parameters - galaxies: ISM -
galaxies: kinematics and dynamics - radio lines: galaxies
Abstract:
We present Arecibo neutral hydrogen data on a sample of optically
selected dwarf galaxies. The sample ranges in H I mass from 106 to
5x109M☉, with a mean of 7.9x108M☉. Using estimated H I
radii, the H I surface densities range from 0.6 to 20M☉/pc2,
all well below the critical threshold for star formation (Kennicutt,
1998ApJ...498..541K 1998ApJ...498..541K). MHI/L values of the LSB dwarfs range from 0.3
to 12 with a mean value of 2.0. Dynamical masses, calculated from the
H I profile widths, range from 108 to 1011M☉. There is a
strong correlation between optical luminosity and dynamical mass for
LSB dwarfs implying that the dark matter (whether baryonic or
nonbaryonic) follows the detectable baryonic matter.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 71 389 LSB Dwarf Galaxy Sample
table2.dat 41 64 Optical and Mass Parameters
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Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 7 A7 --- ESDO Object identification from Schombert et al.,
1997ApJS..111..233S 1997ApJS..111..233S, (1)
10- 11 I2 h RAh Right Ascension (B1950) (2)
13- 14 I2 min RAm Right Ascension (B1950) (2)
16- 19 F4.1 s RAs Right Ascension (B1950) (2)
22- 23 I2 deg DEd Declination (B1950) (2)
25- 26 I2 arcmin DEm Declination (B1950) (2)
28- 29 I2 arcsec DEs Declination (B1950) (2)
32- 36 I5 km/s HVel ? The H I line Heliocentric velocity
measured at the profile midpoint
39- 43 I5 km/s Vel ? The H I line Local Group velocity (3)
46- 48 I3 km/s VWidth ? Velocity width
50 A1 --- Shape [DS] Profile shape (4)
51 A1 --- u_Shape [:] Indicates an uncertain classification
55- 59 I5 mJy.km/s Flux ? Observed integrated 21cm H I line flux
62- 66 F5.2 [solMass] LogHMass ? The log of the H I mass in solar units
69 I1 --- RunCode Observing run number data was taken from (5)
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Note (1): Based on the PSS-II field number and a running number for the
dwarfs found on that field.
Note (2): Measured off the PSS-II plates. Accurate to 15 arcsecs.
Note (3): Velocity calculated according to the precepts of de Vaucouleurs,
de Vaucouleurs, and Corwin (1976, Cat. VII/112).
Note (4): Profile shape
S = single-horned profile
D = double-horned profile
Note (5): Observing runs:
1 = Sample 1 observed in 1986
2 = Sample 2 observed in 1992 and 1993
3 = Sample 3 observed in 1992 and 1993
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 7 A7 --- ESDO Object identification (1)
10- 13 F4.1 arcsec Rad The B band 25 mag isophotal radius
16- 19 F4.2 --- b/a Axial ratio (b/a)
22- 26 F5.1 mag IMag Absolute I band magnitude
29- 33 F5.2 [solMass/pc2] logSdens Log of the H I surface density
36- 40 F5.2 [solMass] LogMass Log of the dynamical mass
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Note (1): Based on the PSS-II field number and a running number for the
dwarfs found on that field.
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History:
* 24-Jan-2001: Prepared by Greg Schwarz [AAS]
* 12-Mar-2001: Corrected coordinates of the 4 sources
500-1, 575-8, 646-1, 721-9 according to Paper I
(in agreement with Jim Schombert)
References:
Schombert et al., Paper I 1997ApJS..111..233S 1997ApJS..111..233S
Pildis et al., Paper II 1997ApJ...481..157P 1997ApJ...481..157P
(End) Greg Schwarz [AAS], Patricia Bauer [CDS] 12-Mar-2001