J/ApJ/627/32 Gravitationally lensed arcs in the HST WFPC2 archive (Sand+, 2005)
A systematic search for gravitationally lensed arcs in the Hubble Space
Telescope WFPC2 archive.
Sand D.J., Treu T., Ellis R.S., Smith G.P.
<Astrophys. J., 627, 32-52 (2005)>
=2005ApJ...627...32S 2005ApJ...627...32S
ADC_Keywords: Clusters, galaxy ; Gravitational lensing
Keywords: galaxies: clusters: general - galaxies: elliptical and lenticular, cD
- gravitational lensing
Abstract:
We present the results of a systematic search for gravitationally
lensed arcs in clusters of galaxies located in the Hubble Space
Telescope Wide Field and Planetary Camera 2 data archive. By carefully
examining the images of 128 clusters we have located 12 candidate
radial arcs and 104 tangential arcs, each of whose length-to-width
ratio exceeds 7. In addition, 24 other radial arc candidates were
identified with a length-to-width ratio of less than 7. Keck
spectroscopy of 17 candidate radial arcs suggests that contamination
of the radial arc sample from nonlensed objects is ∼30%-50%.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table3.dat 84 128 WFPC2 cluster catalog
table4.dat 122 161 Arc list
refs.dat 92 27 References
--------------------------------------------------------------------------------
See also:
B/hst/ : HST Archived Exposures Catalog (STScI, 2006)
J/A+A/407/791 : ACO 370, 2218 and 2390 fluxes at 7 and 15um (Metcalfe+, 2003)
Byte-by-byte Description of file: table3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 9 A9 --- Name Cluster name
11- 12 A2 --- n_Name [ab ] Existence of arc candidates (1)
14- 22 A9 --- PID Program identification number(s)
24- 29 F6.4 --- z Cluster redshift
31- 32 I2 h RAh Hour of Right Ascension (J2000)
34- 35 I2 min RAm Minute of Right Ascension (J2000)
37- 41 F5.2 s RAs Second of Right Ascension (J2000)
43 A1 --- DE- Sign of the Declination (J2000)
44- 45 I2 deg DEd Degree of Declination (J2000)
47- 48 I2 arcmin DEm Arcminute of Declination (J2000)
50- 54 F5.2 arcsec DEs Arcsecond of Declination (J2000)
56- 68 A13 ks ExpTime Exposure time(s)
70- 80 A11 --- Filt Filter(s)
82- 84 A3 --- Sample Cluster sample (2)
--------------------------------------------------------------------------------
Note (1): Flag on Name, defined as follows:
a = Cluster has a radial arc candidate;
b = Cluster has a tangential arc candidate with L/W>7.
Note (2): Cluster sample, defined as follows:
1 = Cluster belongs to Edge Sample;
2 = Cluster belongs to Smith Sample;
3 = Cluster belongs to EMSS Cluster Sample.
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table4.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 9 A9 --- Name Cluster name
11- 28 A18 --- Arc The arc label
29- 30 A2 --- f_Arc [ab*d ] Problematic case (1)
32- 37 F6.4 --- z ? Arc redshift
39- 43 F5.3 --- z2 ? 2nd redshift
45 A1 --- f_z [c] when redshift only for feature H1
47- 49 A3 --- r_z Reference for z
51- 55 F5.2 mag mag1 ? Magnitude of Filt1 observation
57- 60 F4.2 mag e_mag1 ? Uncertainty in mag1
62- 66 F5.2 mag mag2 ? Magnitude of Filt2 observation
68- 71 F4.2 mag e_mag2 ? Uncertainty in mag2
73- 77 F5.2 mag mag3 ? Magnitude of Filt3 observation
79- 82 F4.2 mag e_mag3 ? Uncertainty in mag3
84- 86 I3 nm Flt1 Filter used in first observation
88- 90 I3 nm Flt2 ? Filter used in second observation
92- 94 I3 nm Flt3 ? Filter used in third observation
96 A1 --- l_L/W Limit flag on L/W
97-101 F5.2 --- L/W The length-to-width ratio
103-106 F4.1 --- e_L/W ? Uncertainty in L/W
108-113 F6.2 arcsec Del-N North offset from the cluster center
115-120 F6.2 arcsec Del-E East offset from the cluster center
122 A1 --- Type [RT] Radial (R) or tangential (T) source
--------------------------------------------------------------------------------
Note (1): Flag on Arc, defined as follows:
a = Photometry and L/W may be affected by poor galaxy subtraction or
chip boundary.
b = Unable to detect feature or get reliable photometry in one of the
observed bands.
* = Due to different imaging orientations, this arc only appear in the
F702W image.
d = There is a flat-fielding problem with this portion of the chip for this
image. While this arc is clearly detected in the F814W band, no attempt
was made to correct the flatfielding problem and so no arc magnitude was
recoverable. The L/W for this arc was determined solely from the F555W
band.
--------------------------------------------------------------------------------
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- 49 A26 --- Aut Author's name
51- 92 A42 --- Com Comment
--------------------------------------------------------------------------------
History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Marianne Brouty [CDS] 06-Dec-2005