From: Rachel A. Gibbons (ragibbons@lbl.gov)
Date: Fri Apr 23 2004 - 17:39:48 PDT
Supernovae Discovered with ACS between 2-4 April 2004
R. Gibbons (LBL) on behalf of the Supernova Cosmology Project (cf. IAUC
8119, plus N. Kashikawa, M. Kowalski, N. Kuznetsova, T. Morokuma),
and A. Riess (STScI) on behalf of L. Strolger, H. Ferguson, T. Dahlen,
B. Mobasher (STScI), and P. Challis (CfA), report the discovery of 11
supernovae found with the Advanced Camera for Surveys (ACS) on the Hubble
Space Telescope during the period 02-04 April 2004. Subtractions of
the one year old GOODS HDF-N survey data from new F850LP (z') and F775W
(i') imaging revealed supernovae at signal-to-noise ratios greater than
6 within 0''.2 apertures, but typically well above 15. Search imaging
consisted of sums of four 400s z' exposures and one 400s i' exposure.
Resulting limiting Vega magnitudes in the search data were z'=26.2 and
i'=26.5. The reference images were sums of all the GOODS data taken
between 21-Nov-2002 and 25-May-2003 and reached limiting magnitudes of
z'=27.4 and i'=28.4. None of the objects reported here were present
in the year old references. The brightness of each candidate was
consistent in the individual z' images that went into the z' sums.
Over the ~2100s duration of imaging taken at each search pointing, there
was no evidence of systematic motion indicative of solar system objects.
The limit of our ability to measure such offsets was ~0''.02 (0.2 times
the point spread function FWHM). All reported events appear associated
with host galaxies, none of which show active galaxy variability at the
positions of the candidates over the course of the GOODS survey. For more
information and discovery images please see http://supernova.lbl.gov/.
Supernova are sorted by right ascension.
SN 2004 UT R.A. (2000.0) Decl. z' i' Offset
acs04-193 Apr. 02.74 12 36 19.86 +62 13 48.0 25.1 25.5 0''.07 E, 0''.13 S
acs04-177 02.08 12 36 20.90 +62 10 19.6 25.4 26.3 0''.48 W, 0''.50 S
acs04-176 02.08 12 36 25.93 +62 09 37.4 23.7 ** 0''.04 E, 0''.67 S
acs04-194 02.74 12 36 27.07 +62 15 09.6 24.4 25.1 0''.21 E, 0''.11 S
acs04-185 02.08 12 36 29.44 +62 11 41.9 24.4 24.3 0''.05 W, 0''.04 N
acs04-186 04.71 12 36 46.07 +62 16 25.7 25.8 ** 0''.06 E, 0''.15 S
acs04-181 04.71 12 36 49.36 +62 16 04.8 24.9 25.7 0''.03 E, 0''.00 S
acs04-196 03.40 12 37 06.73 +62 21 17.8 25.4 25.7 0''.05 W, 0''.03 S
acs04-076 03.40 12 37 09.44 +62 22 15.6 25.1 26.5 0''.26 E, 0''.76 N
acs04-197 03.54 12 37 21.32 +62 09 35.2 25.7 >26.5 0''.11 W, 0''.06 N
acs04-195 03.34 12 38 03.58 +62 17 11.9 24.7 25.2 0''.96 W, 0''.18 N
** no i' band measurement
z' and i' are given in Vega magnitudes. Offsets are supernovae position
with respect to host.
This archive was generated by hypermail 2.1.4 : Fri Apr 23 2004 - 17:40:07 PDT