J/AJ/134/169 Redshifts of UDF emission-line objects (Xu+, 2007)
Redshifts of emission-line objects in the Hubble Ultra Deep Field.
Xu C., Pirzkal N., Malhotra S., Rhoads J.E., Mobasher B., Daddi E.,
Gronwall C., Hathi N.P., Panagia N., Ferguson H.C., Koekemoer A.M.,
Kummel M., Moustakas L.A., Pasquali A., Di Serego Alighieri S., Vernet J.,
Walsh J.R., Windhorst R., Yan H.
<Astron. J., 134, 169-178 (2007)>
=2007AJ....134..169X 2007AJ....134..169X
ADC_Keywords: Galaxy catalogs ; Redshifts
Keywords: galaxies: formation - galaxies: high-redshift - galaxies: starburst
Abstract:
We present redshifts for 115 emission-line objects in the Hubble Ultra
Deep Field identified through the Grism ACS Program for Extragalactic
Science (GRAPES) project using the slitless grism spectroscopy mode of
the Advanced Camera for Surveys on the Hubble Space Telescope (HST).
The sample was selected by an emission-line search on all extracted
one-dimensional GRAPES spectra. We identify the emission lines using
line wavelength ratios where multiple lines are detected in the grism
wavelength range (5800Å≲lambda≲9600Å), and using
photometric redshift information where multiple lines are unavailable.
We then derive redshifts using the identified lines.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 92 148 Emission Line Objects in UDF Field
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See also:
II/258 : Hubble Ultra Deep Field Catalog (UDF) (STScI, 2004)
J/AJ/132/926 : Galaxies in the Hubble Ultra Deep Field (Coe+, 2006)
J/AJ/132/1729 : Hubble Ultra Deep Field BVI-dropout sources (Beckwith+, 2006)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 5 I5 --- UDF The UDF identification number (1)
7 A1 --- f_UDF [axcde] Flag on UDF (2)
9- 18 F10.7 deg RAdeg Right Ascension in decimal degrees (J2000)
20- 30 F11.7 deg DEdeg Declination in decimal degrees (J2000)
32- 37 F6.3 mag imag ? The i band (F775W) AB magnitude
39- 44 F6.1 0.1nm lambda Line wavelength in Angstroms
46- 49 F4.1 0.1nm e_lambda Uncertainty in lambda (3)
51- 53 I3 zW/m2 Flux Measured line flux (4)
55- 60 F6.3 --- z ? Redshift
62- 92 A31 --- ID Line identification
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Note (1): Negative numbers do no correspond to UDF (Cat. II/258) numbers.
Note (2): Flags as follows:
a = These objects were identified by the automatic line finding algorithm
x = These objects are manually added into the emission line list
c = Line flux and redshift for object 5225 are taken from
Rhoads et al. (2004ApJ...611...59R 2004ApJ...611...59R)
d = Object 8040 in the UDF catalog corresponds to two distinct
catalog entries in an earlier GRAPES catalog, which likely
correspond to a pair of HII regions in the same galaxy. The two
regions were analyzed separately by "emlinecull", resulting in
two table entries for this object. The total line flux for the
object is approximately the sum of the two entries, while both
have the same redshift within the uncertainties.
e = Line identifications for object 9397 are based on comparison with
the composite quasar spectra of Francis et al.
(1991ApJ...373..465F 1991ApJ...373..465F) and vanden Berk et al.
(2001AJ....122..549V 2001AJ....122..549V). The redshift is based on the MgII line.
Note (3): Wavelength errors are the formal uncertainty from a gaussian fit
to the line. Based on comparison of GRAPES redshifts with VLT
redshifts (see text), we estimate that a systematic error floor of
∼12Å should be applied when the quoted error is smaller.
Note (4): in 10-18erg/cm2/s = 10-21W/m2.
Fluxes quoted here are directly measured from the emission
features falling within the grism extraction window. Because this
window is often relatively narrow, we estimate that the total emission
line flux of an object could exceed the tabulated fluxes by aperture
correction factors in the range of ∼1.5 to ∼3.
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Patricia Vannier [CDS] 22-Aug-2009