J/ApJ/606/L25 Hubble Ultra Deep Parallel Fields (Bouwens+, 2004)
Star formation at z∼6: the Hubble Ultra Deep Parallel Fields.
Bouwens R.J., Illingworth G.D., Thompson R.I., Blakeslee J.P.,
Dickinson M.E., Broadhurst T.J., Eisenstein D.J., Fan X., Franx M.,
Meurer G., Van Dokkum P.
<Astrophys. J., 606, L25-L28 (2004)>
=2004ApJ...606L..25B 2004ApJ...606L..25B
ADC_Keywords: Galaxies, photometry
Keywords: galaxies: evolution - galaxies: high-redshift -
galaxies: luminosity function, mass function
Abstract:
We report on the i-dropouts detected in two exceptionally deep
Advanced Camera for Surveys fields (B435, V606, i775, and z850
with 10σ limits of 28.8, 29.0, 28.5, and 27.8, respectively)
taken in parallel with the Ultra Deep Field Near-Infrared Camera and
Multi-Object Spectrometer observations. Using an i-z>1.4 cut, we find
30 i-dropouts over 21-arcmin2 down to z(850,AB)=28.1, or
1.4 i-dropouts arcmin-2, with significant field-to-field variation
(as expected from cosmic variance). This extends i-dropout searches
some ∼0.9mag further down the luminosity function than was possible in
the Great Observatories Origins Deep Survey (GOODS) fields, yielding a
∼7 times increase in surface density. An estimate of the size
evolution for UV-bright objects is obtained by comparing the composite
radial flux profile of the bright i-dropouts (z(850,AB)<27.2) with
scaled versions of the Hubble Deep Field North and South U-dropouts.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 71 38 z∼6 objects from the UDF Parallel Fields
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See also:
II/258 : Hubble Ultra Deep Field Catalog (UDF) (STScI, 2004)
J/ApJ/612/L93 : Candidates of z∼5.5-7 galaxies in the HST-UDF (Yan+, 2004)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 4 A4 --- --- [UDFP]
5- 15 A11 --- UDFP Object identification, N-NNNN-NNNN (1)
17- 18 I2 h RAh Hour of Right Ascension (J2000)
20- 21 I2 min RAm Minute of Right Ascension (J2000)
23- 28 F6.3 s RAs Second of Right Ascension (J2000)
30 A1 --- DE- Sign of the Declination (J2000)
31- 32 I2 deg DEd Degree of Declination (J2000)
34- 35 I2 arcmin DEm Arcminute of Declination (J2000)
37- 41 F5.2 arcsec DEs Arcsecond of Declination (J2000)
43- 46 F4.1 mag zmag The AB magnitude in the z band
48- 50 F3.1 mag e_zmag Error in zmag
52 A1 --- l_i-z Limit flag on i-z
53- 55 F3.1 mag i-z The AB (i-z) color
57- 60 F4.2 --- sg The star/galaxy separator (0: galaxy; 1: star)
62- 65 F4.2 arcsec rhl Half-light radius
67- 71 A5 --- sample Samples in which object is contained (2)
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Note (1): Selection criteria: (i(775)-z(850))AB>1.4 plus null detection
(<2σ) in V(606). All limits are 2σ. Several different
samples were used in the analysis.
Note (2): Samples are numbered as follows:
1 = Sample #1 was generated by applying our selection criteria to the
undegraded images.
2 = Sample #2 was generated by applying these selection criteria
to the images degraded to match the PSF of the U-dropout sample,
projected to z∼6 (0.14" FWHM)
3 = Sample #3 was generated by applying these selection criteria
to the images degraded to match the PSF of the B-dropout sample,
projected to z∼6 (10" FWHM).
Images from the latter samples were degraded to a uniform S/N
equivalent to 5 orbit V(606), 10 orbit i(775), and 15 orbit z(850)
observations. The union of all three samples (38 objects) is larger
than the undegraded sample (sample #1) due to object blending and
photometric scatter. UDFP1 and UDFP2 refer to the first and second UDF
parallels, respectively.
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Patricia Vannier [CDS] 07-May-2004