J/ApJ/682/1205 Fast transients in the Fornax cluster (Rau+, 2008) ================================================================================ A survey for fast transients in the Fornax cluster of galaxies. Rau A., Ofek E.O., Kulkarni S.R., Madore B.F., Pevunova O., Ajello M. =2008ApJ...682.1205R ================================================================================ ADC_Keywords: Stars, variable ; Photometry, CCD Keywords: delta Scuti - stars: flare - stars: variables: other - surveys Abstract: The luminosity gap between novae (M_R_<=-10) and supernovae (M_R_>=-14) has been well known since the pioneering research of Zwicky and Hubble. Nearby galaxy clusters and concentrations offer an excellent opportunity to search for explosions brighter than classical novae and fainter than supernovae. Here we present the results of a B-band survey of 23 member galaxies of the Fornax Cluster, performed at the Las Campanas 2.5m Irenee du Pont telescope. Observations with a cadence of 32 minutes discovered no genuine fast transient to a limiting absolute magnitude of M_B_=-9.3mag. We provide a detailed assessment of the transient detection efficiency and the resulting upper limits on the event rate as function of peak magnitude. Further, we discuss the discoveries of five previously unknown foreground variables which we identified as two flare stars, two W UMa-type eclipsing binaries and a candidate {delta} Scuti/SX Phe star. Description: Observations were obtained with the Wide Field Reimaging CCD Camera (WFCCD) at the 2.5m Irenee du Pont telescope in Las Campanas, Chile. For the survey, we selected 10 fields covering the 23 brightest Fornax I Cluster members. These fields were imaged with a sequence of 120s exposures repeated up to 15 times in each of five nights in 2006 October and December. File Summary: -------------------------------------------------------------------------------- FileName Lrecl Records Explanations -------------------------------------------------------------------------------- ReadMe 80 . This file table3.dat 99 7 Summary of detected sources table4.dat 27 385 Data table for the 5 foreground variables found in the survey -------------------------------------------------------------------------------- See also: J/PASP/110/533 : BR photometry of Fornax bright stars (Stetson+ 1998) J/A+A/317/54 : Fornax cluster 1 and 3 photometry (Jorgensen+ 1997) J/AJ/111/1596 : BV photometry in Fornax globulars (Smith+ 1996) Byte-by-byte Description of file: table3.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 9 A9 --- Name Source identification (<[ROK2008] FA-1> in Simbad for the 5 new variables) 11- 12 I2 h RAh Hour of right ascension (J2000) 14- 15 I2 min RAm Minute of right ascension (J2000) 17- 21 F5.2 s RAs Second of right ascension (J2000) 23 A1 --- DE- Declination sign (J2000) 24- 25 I2 deg DEd Degree of declination (J2000) 27- 28 I2 arcmin DEm Arcminute of declination (J2000) 30- 33 F4.1 arcsec DEs Arcsecond of declination (J2000) 35- 39 F5.2 mag Bmag Observed peak B-band magnitude 41- 44 F4.2 mag e_Bmag Uncertainty in Bmag 45 A1 --- f_Bmag [de] Flag on Bmag (1) 47- 51 F5.2 mag Bq ? Mean or quiescence B-band magnitude (2) 53- 56 F4.2 mag e_Bq ? Uncertainty in Bq 58- 78 A21 --- Class Class of object 80- 83 F4.1 kpc Dist Projected distance to center of nearest galaxy 85- 94 A10 --- --- [kpc to NGC] 96- 99 I4 --- NGC NGC number of nearest galaxy -------------------------------------------------------------------------------- Note (1): Flags as follows: d = Observed B-band magnitude on 2006 October 23.13 UT. e = Observed B-band magnitude on 2006 November 17.58 UT. Note (2): Observed mean (for periodic variables) or quiescence (for eruptive variables) B-band magnitude. -------------------------------------------------------------------------------- Byte-by-byte Description of file: table4.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 4 A4 --- Name Source name 6- 16 F11.5 d MJD Modified Julian Date 18- 22 F5.2 mag Bmag The B band magnitude 24- 27 F4.2 mag e_Bmag Error in Bmag -------------------------------------------------------------------------------- History: From electronic version of the journal ================================================================================ (End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 24-Nov-2010