Access to Astronomical Catalogues

← Click to display the menu
J/AJ/140/1194       FUV/HI relations in nearby galaxies      (Bigiel+, 2010)

Extremely inefficient star formation in the outer disks of nearby galaxies. Bigiel F., Leroy A., Walter F., Blitz L., Brinks E., De Blok W.J.G., Madore B. <Astron. J., 140, 1194-1213 (2010)> =2010AJ....140.1194B
ADC_Keywords: Galaxies, nearby ; Galaxies, radio ; H I data ; Ultraviolet Keywords: galaxies: evolution - galaxies: ISM - radio lines: galaxies - stars: formation Abstract: We combine data from The HI Nearby Galaxy Survey and the GALEX Nearby Galaxy Survey to study the relationship between atomic hydrogen (HI) and far-ultraviolet (FUV) emission outside the optical radius (r25) in 17 spiral and 5 dwarf galaxies. In this regime, HI is likely to represent most of the interstellar medium (ISM) and FUV emission to trace recent star formation with little bias due to extinction, so that the two quantities closely trace the underlying relationship between gas and star formation rate (SFR). Description: We study 22 galaxies: 17 spiral and 5 dwarf galaxies. This sample is constructed from the overlap of THINGS (Walter et al., 2008, Cat. J/AJ/136/2563) and targets of the GALEX NGS (Gil de Paz et al., 2007, Cat. J/ApJS/173/185) that were observed to similar depth (integration time of ≳1.5ks, corresponding to at least one orbit, which is the standard integration time for GALEX NGS targets). File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table1.dat 62 29 Sample properties table2.dat 56 4478 Data for individual sampling points from the optical disks (r<r25) table3.dat 42 36777 Data for individual sampling points from the outer disks (r>r25)
See also: J/ApJS/173/185 : GALEX ultraviolet atlas of nearby galaxies (Gil de Paz+, 2007) J/AJ/136/2563 : HI Nearby Galaxy Survey, THINGS (Walter+, 2008) Byte-by-byte Description of file: table1.dat
Bytes Format Units Label Explanations
1- 7 A7 --- Sample Galaxy sample (G1) 9- 19 A11 --- Name Galaxy name (2) 21- 24 F4.1 Mpc Dist ? Distance 26- 27 I2 deg i ? Inclination 29- 31 I3 deg PA ? Position angle 33- 36 F4.1 arcmin r25 ? Angular isophotal radius corresponding to 28 B-band magnitudes per square arcsecond 38- 41 F4.1 kpc r25l ? Linear isophotal radius corresponding to 28 B-band magnitudes per square arcsecond 43- 46 A4 --- HType Hubble type 47 A1 --- n_Name [*] * when galaxy and HType added by CDS 51- 62 A12 --- SName Simbad name
Note (2): See Walter et al. (2008, Cat. J/AJ/136/2563) for further information on individual galaxies and for references to the values quoted in this table.
Byte-by-byte Description of file: table2.dat
Bytes Format Units Label Explanations
1- 7 A7 --- Sample Galaxy sample (G1) 14- 24 A11 --- Name Galaxy name (2) 26- 29 F4.2 [Msun/pc2] logHI ? Log HI surface density (3) 31- 34 F4.2 [Msun/pc2] e_logHI Uncertainty in logHI (4) 36- 39 F4.2 [Msun/pc2] logH2 ? Log H_2_ surface density (3) 41- 44 F4.2 [Msun/pc2] e_logH2 ? Uncertainty in logH2 (4) 46- 50 F5.2 [Msun/yr/kpc2] logSFR Log SFR surface density (3) 52- 56 F5.2 [Msun/yr/kpc2] e_logSFR ? Uncertainty in logSFR (4)
Note (2): References: * Sampling points and this result: Bigiel et al. (2008AJ....136.2846B) * HI Maps: THINGS, Walter et al. (2008, Cat. J/AJ/136/2563) * Galaxy Distance and Orientation: Walter et al. (2008, Cat. J/AJ/136/2563) * SFR Maps: SINGS IR (Kennicutt et al., 2003PASP..115..928K), GALEX FUV (Gil de Paz et al. 2007, Cat. J/ApJS/173/185), combination (Leroy et al. 2008, Cat. J/AJ/136/2782) * CO Maps: HERACLES (Leroy et al., 2009AJ....137.4670L), BIMA SONG (only NGC 5194, Helfer et al., 2003ApJS..145..259H). Note (3): Contrary to the paper, HI and H2 surface densities include a factor of 1.36 to account for helium. The data were sampled at a common physical resolution of 750pc. Surface densities are corrected to account for inclination. * Assumptions to convert CO to H2: XCO = 2*1020cm-2/(K.km/s), I(2-1)/I(1-0) = 0.8. * Star formation rate is traced by UV and IR emission. * Calibration assumes a Kroupa IMF. * Data points are roughly independent, but slight oversampling does occur in some regions. Note (4): * HI sensitivity ∼1M/pc2, calibration uncertainty ∼10%. * H2 sensitivity (only in spiral sample) ∼4M/pc2 (HERACLES) or ∼13M_☉/pc2 (BIMA SONG), calibration uncertainty ∼25%, * XCO uncertainty not included but we suggest 50%. * SFR sensitivity ∼2*104M/yr/kpc^2, calibration uncertainty ∼50% but covariant within a galaxy (from comparison with other tracers). * No value indicates an upper limit for the given value (in cases where there is no data (NaN) or the measurement is not significant).
Byte-by-byte Description of file: table3.dat
Bytes Format Units Label Explanations
1- 7 A7 --- Sample Galaxy sample (G1) 9- 19 A11 --- Name Galaxy name (2) 21- 25 F5.2 [Msun/pc2] logHI Log HI surface density (3) 27- 30 F4.2 [Msun/pc2] e_logHI Uncertainty in logHI (4) 32- 37 F6.2 10-5Msun/yr/kpc2 SFR SFR surface density (3) 39- 42 F4.2 10-5Msun/yr/kpc2 e_SFR ? Uncertainty in SFR (4)
Note (2): References: * Sampling points and this result: Bigiel et al. (2010ApJ...720L..31B). * HI Maps: THINGS, Walter et al. (2008, Cat. J/AJ/136/2563). * Galaxy Distance and Orientation: Walter et al. (2008, Cat. J/AJ/136/2563). * SFR Maps: Based on GALEX far FUV (Gil de Paz et al., 2007, Cat. J/ApJS/173/185, Salim et al., 2007ApJS..173..267S). Note (3): Contrary to the paper, a factor of 1.36 to account for helium is included in the HI surface densities. The data were sampled at a common angular resolution of 15 arcsec. Note that many of the SFR (FUV) data are below the sensitivity used in Bigiel et al. (2010ApJ...720L..31B). It is thus especially important to pay attention to averaging and uncertainties when using these data. Note that HI surface densities are logarithms, while SFR surface densities are not. Surface densities are corrected to account for inclination. The SFR surface densities are directly proportional to far UV intensity. The calibration assumes a Chabrier IMF. Data points are roughly independent, but slight oversampling does occur in some regions. Note (4): * HI sensitivity ∼0.4M/pc2, calibration uncertainty ∼10%. Data below the HI sensitivity is discarded. * SFR(FUV): sensitivity ∼2*10-5M/yr/kpc2, uncertainty ∼7*10-6M/yr/kpc2. Note that this is the uncertainty (noise) in the FUV map and takes no account of the (significant) uncertainty translating FUV intensity into SFR surface densities. * No value indicates an upper limit for the given value (in cases where there is not SFR (FUV) data (NaN) or the measurement is not significant).
Global Notes: Note (G1): Sample is: Dwarfs = dwarf galaxy sample from Bigiel et al. (2010ApJ...720L..31B) Spirals = spiral galaxy sample from Bigiel et al. (2010ApJ...720L..31B) Spiral2 = the sample of spiral galaxies with H2-dominated centers from Bigiel et al. (2008AJ....136.2846B) (in table2 only) HI-dom = sample of HI-dominated galaxies from Bigiel et al. (2008AJ....136.2846B), not in original table1, but in table2.
History: From electronic version of the journal
(End) Greg Schwarz [AAS], Patricia Vannier [CDS] 30-Jun-2012
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

catalogue service

© UDS/CNRS

Contact