J/AJ/128/2170 H{alpha} imaging of irregular galaxies (Hunter+, 2004) ================================================================================ Star formation properties of a large sample of irregular galaxies. Hunter D.A., Elmegreen B.G. =2004AJ....128.2170H ================================================================================ ADC_Keywords: Photometry, H-alpha ; Galaxies, photometry Keywords: galaxies: irregular - stars: formation Abstract: We present the results of H{alpha} imaging of a large sample of irregular galaxies. Our sample includes 94 galaxies with morphological classifications of Im, 26 blue compact dwarfs (BCDs), and 20 Sm systems. The sample spans a large range in galactic parameters, including integrated absolute magnitude (M_V_ of -9 to -19), average surface brightness (20-27mag/arcsec^2^), current star formation activity (0-1.3M_{Sun}_/yr/kpc^2^), and relative gas content (0.02-5M_{Sun}_/LB). The H{alpha} images were used to measure the integrated star formation rates, determine the extents of star formation in the disks, and compare azimuthally averaged radial profiles of current star formation to older starlight. Description: The H{alpha} images were obtained in 22 observing runs from 1988 to 1998. File Summary: -------------------------------------------------------------------------------- FileName Lrecl Records Explanations -------------------------------------------------------------------------------- ReadMe 80 . This file table3.dat 77 140 H{alpha} Photometry, Star Formation Rates, H{alpha} Extents table4.dat 41 140 Other Parameters refs.dat 84 25 References -------------------------------------------------------------------------------- Byte-by-byte Description of file: table3.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 3 A3 --- MType Galaxy type 5- 15 A11 --- Name Galaxy name 17- 21 F5.2 [10-7W] logHa Logarithm of the reddening-corrected H{alpha} luminosity 23- 26 F4.2 [10-7W] e_logHa ? Error in logHa 28- 32 F5.2 [solMass/yr] logMd ? Logarithm of the star formation rate 34- 38 F5.2 [solMass/yr/kpc2] logM25 ? Logarithm of the integrated star formation rate normalized to the area of the galaxy within R_25_ 40- 44 F5.2 [solMass/yr/kpc2] logMD ? Logarithm of the integrated star formation rate normalized to the area of the galaxy within R_D_ 46- 50 F5.2 [yr] logtau ? Logarithm of the time to exhaust the total current galaxy gas content at the current star formation rate 52- 56 F5.2 arcmin RHa ? Semimajor axis of largest ellipse that contains H{alpha} emission (1) 58- 61 F4.2 arcmin RHII ? Semimajor axis of largest ellipse that contains the center of a discrete H{alpha} region (1) 63- 66 F4.2 --- RHII/R25 ? Ratio of the furthest detectable discrete H{alpha} region radius to the B-band surface brightness of 25mag/arcsec^2^ radius 68- 71 F4.2 --- RHII/RH ? Ratio of the furthest detectable discrete H{alpha} region radius to the Holmberg radius 73- 76 F4.2 --- RHII/RD ? Ratio of the furthest detectable discrete H{alpha} region radius to disk scale length -------------------------------------------------------------------------------- Note (1): 99.99 = The H{alpha} potentially extended beyond the region that we imaged. -------------------------------------------------------------------------------- Byte-by-byte Description of file: table4.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 3 A3 --- MType Galaxy type 5- 15 A11 --- Name Galaxy name 17- 21 F5.2 kpc R25 ? B-band 25mag/arcsec^2^ radius 23- 26 F4.2 kpc RD ? Disk scale length 28- 33 F6.2 mag VMAG ? Absolute V-band magnitude 35- 38 F4.2 [solMass] logM ? Logarithm of the total galactic atomic gas mass (1) 40- 41 I2 --- r_logM ? The HI mass reference -------------------------------------------------------------------------------- Note (1): The HI mass has been multiplied by 1.34 to account for He. -------------------------------------------------------------------------------- Byte-by-byte Description of file: refs.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 2 I2 --- Ref Reference number 4- 22 A19 --- Bibcode Bibcode 24- 43 A20 --- Aut Author's name 45- 84 A40 --- Com Comments -------------------------------------------------------------------------------- History: From electronic version of the journal ================================================================================ (End) Greg Schwarz [AAS], Marianne Brouty [CDS] 20-Apr-2005