J/ApJ/705/68 A Spitzer ultradeep survey (SUUSS) (Bertincourt+, 2009)
A Spitzer Unbiased Ultradeep Spectroscopic Survey.
Bertincourt B., Helou G., Appleton P., Ogle P., Lagache G., Brooke T.,
Smith J.-D., Sheth K., Dale D., Harwit M., Puget J.-L., Roussel H.
<Astrophys. J., 705, 68-88 (2009)>
=2009ApJ...705...68B 2009ApJ...705...68B
ADC_Keywords: Galaxies, spectra ; Galaxies, IR ; Redshifts
Keywords: galaxies: starburst - infrared: galaxies
Abstract:
We carried out an unbiased, spectroscopic survey using the
low-resolution module of the infrared spectrograph (IRS) onboard
Spitzer targeting two 2.6 square arcminute regions in the GOODS-North
field. The IRS was used in a spectral mapping mode with 5hr of
effective integration time per pixel. One region was covered between
14 and 21um and the other between 20 and 35um. We extracted spectra
for 45 sources. About 84% of the sources have reported detections by
GOODS at 24um, with a median fν(24um)∼100uJy. All but one source
are detected in all four IRAC bands, 3.6 to 8um. We use a new
cross-correlation technique to measure redshifts and estimate IRS
spectral types; this was successful for ∼60% of the spectra. Fourteen
sources show significant polycyclic aromatic hydrocarbon emission,
four mostly SiO absorption, eight present mixed spectral signatures
(low PAH and/or SiO) and two show a single line in emission. For the
remaining 17, no spectral features were detected. Redshifts range from
z∼0.2 to z∼2.2, with a median of 1. IR luminosities are roughly
estimated from 24um flux densities, and have median values of
2.2x1011L☉ and 7.5x1011L☉ at z∼1 and z∼2,
respectively. This sample has fewer active galactic nuclei than
previous faint samples observed with the IRS, which we attribute to
the fainter luminosities reached here.
Description:
We chose to place the survey in the Hubble Deep Field North (HDF-N)
covered in the infrared by Spitzer as part of the GOODS survey
(Dickinson et al. 2003mglh.conf..324D; see also Cat. II/261). We
observed a region in the HDF-N (Figure 1) with the Long-Low module of
the IRS onboard Spitzer. Data are collected simultaneously from the
two slits (LL1 and LL2) of the low-resolution module of the IRS, which
cover different spectral ranges (14-21um and 20-38um).The survey was
executed using eight Astronomical Observation Requests (AORs) for a
total of 46.5hr of observation.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 51 45 Source extraction information
table2.dat 80 45 Spitzer multi-wavelength data
table4.dat 40 33 Cross-correlation analysis results
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See also:
II/261 : GOODS initial results (Giavalisco+, 2004)
J/A+A/528/A35 : Infrared luminosity in GOODS fields (Magnelli+, 2011)
J/ApJS/187/251 : Ultradeep Ks imaging in the GOODS-N (Wang+, 2010)
J/ApJ/689/687 : GOODS-N spectroscopic survey (Barger+, 2008)
J/ApJ/666/863 : GOODS MIPS early-type galaxies (Van Der Wel+, 2007)
J/MNRAS/371/1891 : GOODS ELAIS-N1 24um flux densities (Rodighiero+, 2006)
J/ApJ/653/1004 : Galaxies at 1.4≲z≲3.0 in GOODS-North Field (Reddy+, 2006)
J/ApJ/634/128 : 16µm imaging around the HDF-N (Teplitz+, 2005)
J/AJ/127/3121 : TKRS catalog of GOODS-North Field (Wirth+, 2004)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 5 A5 --- --- [SUUSS]
7- 8 I2 --- SUUSS Source number
9 A1 --- f_SUUSS [d] Flag on SUUSS 9 (1)
11- 13 A3 --- Field Field (LL1: IRS low-resolution (20-35um) or LL2:
IRS low-resolution (14-21um))
15- 21 F7.3 deg RAdeg Spitzer/IRS right ascension in decimal degrees
(J2000)
23- 29 F7.4 deg DEdeg Spitzer/IRS declination in decimal degrees
(J2000)
31- 34 F4.1 --- S/N Signal to noise ratio estimation (2)
36- 39 F4.1 um S/Npk Maximum S/N (3)
41- 45 F5.2 um Wpk Wavelength at which the spectrum peaks (3)
47- 51 F5.2 um DelL Contracted spectral bandwidth over which the
spectra have flux densities higher than 2σ
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Note (1):
d = SUUSS 9 is the [SIV] line source discussed in Section 4.3 which
explains the low integrated S/N compared to its peak S/N.
Note (2): S/N estimation when fluxes are integrated over the whole spectral
range available (14-20um for LL2 and 20-35um for LL1).
Note (3): Maximum S/N achieved in each spectrum and the wavelength at which
it peaks. The spectra were smoothed using a comprehensive Hanning
window over three channels in order to avoid contribution from any
potentially remaining hot pixel value.
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 5 A5 --- --- [SUUSS]
7- 8 I2 --- SUUSS Source number
10- 16 F7.3 deg RAdeg Spitzer/IRS right ascension in decimal degrees
(J2000)
18- 24 F7.4 deg DEdeg Spitzer/IRS declination in decimal degrees (J2000)
26- 30 F5.2 uJy S3.6 ? Spitzer/IRAC 3.6um band flux (4)
32- 35 F4.2 uJy e_S3.6 ? S3.6 uncertainty
37- 41 F5.2 uJy S4.5 ? Spitzer/IRAC 4.5um band flux (4)
43- 46 F4.2 uJy e_S4.5 ? S4.5 uncertainty
48- 53 F6.3 uJy S5.8 ? Spitzer/IRAC 5.8um band flux (4)
55- 58 F4.2 uJy e_S5.8 ? S5.8 uncertainty
60- 65 F6.2 uJy S8.0 ? Spitzer/IRAC 8um band flux (4)
67- 70 F4.2 uJy e_S8.0 ? S8.0 uncertainty
72- 76 F5.1 uJy S24 ? Spitzer/MIPS 24um band flux (5)
78- 80 F3.1 uJy e_S24 ? S24 uncertainty
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Note (4): IRAC photometry from GOODS legacy program, Dickinson et al.
(2003mglh.conf..324D; see also Cat. II/261).
Note (5): MIPS 24um photometry from GOODS-N, Chary (2007ASPC..380..375C 2007ASPC..380..375C).
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 5 A5 --- --- [SUUSS]
7- 8 I2 --- SUUSS Source number
9 A1 --- f_SUUSS [c] no conclusive identification (1)
11 I1 --- Field [1/2] Field number (1: LL1 or 2: LL2)
13- 16 F4.2 --- zIRS ? Redshift from Spitzer/IRS
18- 21 F4.2 --- z ? Redshift from litterature
23 A1 --- r_z [P/S]? Code reference for z (2)
25- 34 A10 --- Template Template (galaxy prototype or PAH-class)
36- 40 A5 --- SpT Spectral characterisation (3)
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Note (1):
c = Sources with no conclusive identification from the cross-correlation
method but for which we had ancilliary redshifts (same reference).
Note (2): Code as follows:
S = Spectroscopic redshifts from the Treasurey Keck Redshift Survey (Wirth et
al. 2004, Cat. J/AJ/127/3121)
P = Photometric redshifts from Caputi et al. (2006ApJ...637..727C 2006ApJ...637..727C)
Note (3): Main spectral signature identified in the MIR spectra as follows:
PAH = strong aromatic features,
SiO = silicate absorption,
Mixed = intermediate spectra,
Line = the two special line-sources ([SIV] and [OIV]) discussed in
Section 4.3.
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History:
From electronic version of the journal
(End) Emmanuelle Perret [CDS] 29-Nov-2011