J/A+A/379/798 ELAIS H{alpha} emitting galaxies (Pascual+, 2001) ================================================================================ H{alpha} emitting galaxies and the star formation rate density at z =~ 0.24. Pascual S., Gallego J., Aragon-Salamanca A., Zamorano J. =2001A&A...379..798P ================================================================================ ADC_Keywords: Galaxies, photometry ; Equivalent widths Keywords: galaxies: distances and redshifts - galaxies: evolution - galaxies: luminosity function, mass function Abstract: We have carried out a survey searching for H{alpha} emitting galaxies at z~0.24 using a narrow band filter tuned with the redshifted line. The total sky area covered was 0.19 square degrees within the redshift range 0.228 to 0.255 in a set of four fields in the ELAIS-N1 zone. This corresponds to a volume of 9.8x10^3^Mpc^3^ and a look-back time of 3.6Gyr when H=50km/s/Mpc and q=0.5 are assumed. A total of 52 objects are selected as candidates for a broad band limiting magnitude of I~22.9, plus 16 detected only in the narrow band image for a narrow band limiting magnitude for object detection of 21.0. The threshold detection corresponds to about 20{AA} equivalent width with an uncertainty of ~+/-10{AA}. Point-like objects (15) were excluded from our analysis using CLASS_STAR parameter from SExtractor. The contamination from other emission lines such as [O II]{lambda}3727, H{beta} and [OIII]{lambda}{lambda}4959,5007 at redshifts 1.2, 0.66 and 0.61 respectively is estimated, and found to be negligible at the flux limits of our sample. We find an extinction-corrected H{alpha} luminosity density of (5.4+/-1.1)x10^39^erg/s/Mpc^3^. Our survey for H{alpha} emitting galaxies was carried out using the focal reducer CAFOS at the 2.2 m telescope in CAHA (Centro Astronomico Hispano-Aleman, Almeria, Spain). This instrument is equipped with a 2048x2048 Site#1d CCD with 24{mu}m pixels (0.53" on the sky), which covers a circular area of 16'diameter. File Summary: -------------------------------------------------------------------------------- FileName Lrecl Records Explanations -------------------------------------------------------------------------------- ReadMe 80 . This file table2.dat 66 69 Objects selected in the fields ELAIS a3, a4, b3 and b4 with measurements. -------------------------------------------------------------------------------- See also: J/MNRAS/302/222 : ISO ELAIS 20cm VLA survey regions (Ciliegi+, 1999) J/MNRAS/305/297 : ISO ELAIS 1.4GHz survey (Gruppioni+, 1999) Byte-by-byte Description of file: table2.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 2 A2 --- Field ELAIS field name (1) 4- 8 I5 --- ID Identification number in the ELAIS field (1) 9 A1 --- n_ID [ab] Note on ID (2) 11- 12 I2 h RAh Right ascension (J2000) 14- 15 I2 min RAm Right ascension (J2000) 17- 20 F4.1 s RAs Right ascension (J2000) 22 A1 --- DE- Declination sign (J2000) 23- 24 I2 deg DEd Declination (J2000) 26- 27 I2 arcmin DEm Declination (J2000) 29- 33 F5.2 arcsec DEs Declination (J2000) 35 A1 --- l_Imag Limit flag on Imag 36- 39 F4.1 mag Imag I Cousins magnitude 42- 45 F4.1 mag Hamag H{alpha} narrow band (816nm) magnitude 47 A1 --- l_EWHa Limit flag on EWHa 48- 51 I4 0.1nm EWHa H{alpha} equivalent width 53- 56 F4.1 --- sigma sigma excess of the detection 58- 61 F4.2 --- IClass CLASS_STAR parameter produced by SExtractor in Cousins I band image (3) 63- 66 F4.2 --- HaClass CLASS_STAR parameter produced by SExtractor in H{alpha} narrow band image (3) -------------------------------------------------------------------------------- Note (1): Identified as [PGA2001] ELAIS aN NNNNN in Simbad a3_551 and a4_10732 are the same object. Note (2): a: Selected under the broad limit magnitude b: Catalogued as star Note (3): SExtractor CLASS_STAR parameter: 0 = galaxy 1 = star -------------------------------------------------------------------------------- History: From electronic version of the journal ================================================================================ (End) James Marcout, Patricia Bauer [CDS] 29-Jan-2002