J/ApJ/812/43 ALMA 870um obs. of HerMES galaxies (Bussmann+, 2015)
HerMES: ALMA imaging of Herschel-selected dusty star-forming galaxies.
Bussmann R.S., Riechers D., Fialkov A., Scudder J., Hayward C.C.,
Cowley W.I., Bock J., Calanog J., Chapman S.C., Cooray A., De Bernardis F.,
Farrah D., Fu H., Gavazzi R., Hopwood R., Ivison R.J., Jarvis M., Lacey C.,
Loeb A., Oliver S.J., Perez-Fournon I., Rigopoulou D., Roseboom I.G.,
Scott D., Smith A.J., Vieira J.D., Wang L., Wardlow J.
<Astrophys. J., 812, 43 (2015)>
=2015ApJ...812...43B 2015ApJ...812...43B (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies, IR ; Photometry, millimetric/submm ;
Gravitational lensing ; Surveys
Keywords: galaxies: evolution; submillimeter: galaxies;
techniques: interferometric
Abstract:
The Herschel Multi-tiered Extragalactic Survey (HerMES, Oliver et al.
2012, VIII/95) has identified large numbers of dusty star-forming
galaxies (DSFGs) over a wide range in redshift. A detailed
understanding of these DSFGs is hampered by the limited spatial
resolution of Herschel. We present 870µm 0.45" resolution imaging
obtained with the Atacama Large Millimeter/submillimeter Array (ALMA)
of a sample of 29 HerMES DSFGs that have far-infrared (FIR) flux
densities that lie between the brightest of sources found by Herschel
and fainter DSFGs found via ground-based surveys in the submillimeter
region. The ALMA imaging reveals that these DSFGs comprise a total of
62 sources (down to the 5σ point-source sensitivity limit in our
ALMA sample; σ∼0.2mJy). Optical or near-infrared imaging
indicates that 36 of the ALMA sources experience a significant flux
boost from gravitational lensing (µ>1.1), but only six are strongly
lensed and show multiple images. We introduce and make use of
uvmcmcfit, a general-purpose and publicly available Markov chain Monte
Carlo visibility-plane analysis tool to analyze the source properties.
Combined with our previous work on brighter Herschel sources, the lens
models presented here tentatively favor intrinsic number counts for
DSFGs with a break near 8mJy at 880um and a steep fall-off at higher
flux densities. Nearly 70% of the Herschel sources break down into
multiple ALMA counterparts, consistent with previous research
indicating that the multiplicity rate is high in bright sources
discovered in single-dish submillimeter or FIR surveys. The ALMA
counterparts to our Herschel targets are located significantly closer
to each other than ALMA counterparts to sources found in the LABOCA
ECDFS Submillimeter Survey. Theoretical models underpredict the excess
number of sources with small separations seen in our ALMA sample. The
high multiplicity rate and small projected separations between sources
seen in our sample argue in favor of interactions and mergers
plausibly driving both the prodigious emission from the brightest
DSFGs as well as the sharp downturn above S880=8mJy.
Description:
ALMA 870um data were obtained during Cycle 0 from 2012 June to
December (Program 2011.0.00539.S; PI: D. Riechers).
Optical imaging observations (ugriz) using the Gemini Multi-Object
Spectrograph-South (GMOS-S) were conducted in queue mode during the
2013B semester as part of program GS-2013B-Q-77 (PI: R. S. Bussmann).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 114 82 Observed positions and flux densities of
ALMA sources for 29 HerMES dusty star-forming
galaxies (DSFGs)
table2.dat 68 22 Lens properties from parameters of model fits
to ALMA sources
table3.dat 88 63 Intrinsic properties from parameters of model
fits to ALMA sources
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See also:
VI/139 : Herschel Observation Log (Herschel Science Centre, 2013)
III/334 : VISTA Deep Extragalactic Observations (VIDEO) (Jarvis+, 2013)
VIII/95 : Herschel Multi-tiered Extragalactic Survey (Oliver+, 2012)
VIII/65 : 1.4GHz NRAO VLA Sky Survey (NVSS) (Condon+ 1998)
J/MNRAS/442/577 : Selected ALESS submm galaxies radio data (Thomson+, 2014)
J/ApJ/768/91 : ALMA observations of LESS submm galaxies (Hodge+, 2013)
J/ApJ/761/140 : Spectroscopy of Herschel-SPIRE galaxies (Casey+, 2012)
J/ApJ/745/95 : Herschel FIR+submm photom. of KINGFISH sample (Dale+, 2012)
J/A+A/543/A161 : Submm obs. of 323 HRS nearby galaxies (Ciesla+, 2012)
J/ApJ/707/1201 : LABOCA ECDFS Submillimeter Survey (LESS) (Weiss+, 2009)
J/MNRAS/385/2225 : AzTEC millimetre survey of COSMOS field (Scott+, 2008)
J/MNRAS/380/199 : SCUBA Half-Degree Extragalactic Survey. III (Ivison+, 2007)
J/ApJ/622/772 : Redshift survey of submillimeter galaxies (Chapman+, 2005)
http://hermes.sussex.ac.uk/ : HerMES project home page
http://hedam.lam.fr/HerMES/ : Herschel Database in Marseille - HerMES data
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 12 A12 --- --- [1HerMES S250]
14- 30 A17 --- 1HerMES Herschel S250 Source (JHHMMSS.s+DDMMSS) (1)
31- 39 A9 --- ALMA Short Name; ALMA Source
41- 42 I2 h RAh 870um Hour of Right Ascension (J2000) (2)
44- 45 I2 min RAm Minute of Right Ascension (J2000) (2)
47- 52 F6.3 s RAs Second of Right Ascension (J2000) (2)
54 A1 --- DE- 870um Sign of the Declination (J2000) (2)
55- 56 I2 deg DEd 870um Degree of Declination (J2000) (2)
58- 59 I2 arcmin DEm Arcminute of Declination (J2000) (2)
61- 65 F5.2 arcsec DEs Arcsecond of Declination (J2000) (2)
67- 69 I3 mJy S250 [19/179]? Herschel SPIRE 250um flux density
71 I1 mJy e_S250 [6/7]? Uncertainty in S250 (3)
73- 75 I3 mJy S350 [39/188]? Herschel SPIRE 350um flux density
77 I1 mJy e_S350 [5/8]? Uncertainty in S350 (3)
79- 81 I3 mJy S500 [52/134]? Herschel SPIRE 500um flux density
83- 84 I2 mJy e_S500 [5/11]? Uncertainty in S500 (3)
86- 90 F5.2 mJy S870 [0.9/63.4] ALMA 870um flux density
92- 95 F4.2 mJy e_S870 [0.1/1.4] Uncertainty in S870 (3)
97-100 F4.2 mJy sig [0.1/0.3]? ALMA map statistical rms, σ
102-105 F4.2 arcsec a [0.4/0.7]? ALMA map synthesized beam major axis
FWHM (Ωa)
107-110 F4.2 arcsec b [0.3/0.5]? ALMA map synthesized beam minor axis
FWHM (Ωb)
112 A1 --- Grade [ACX] Lens Grade (A=strongly lensed;
C=weakly lensed; X=unlensed)
114 I1 --- L ? Number of lens data (link to table 2);
column added by CDS
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Note (1): <1HerMES S250 JHHMMSS.s+DDMMSS> in Simbad
Note (2): Positional uncertainties (for unlensed sources) range from 0.005"
for well-detected sources to 0.15" for the faintest sources in our
sample.
Note (3): Uncertainties in flux density do not include the absolute calibration
uncertainty of 10%. Quoted uncertainties in Herschel photometry are
dominated by confusion noise Nguyen et al. (2010A&A...518L...5N 2010A&A...518L...5N).
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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- 15 A15 --- Name Short name of the lens
17- 21 F5.2 arcsec oRA [-3.6/4.5] Right ascension offset (1)
23- 26 F4.2 arcsec e_oRA [0.01/0.2]? oRA uncertainty (2)
28- 32 F5.2 arcsec oDE [-4.5/3] Declination offset (1)
34- 37 F4.2 arcsec e_oDE [0.01/0.3]? oDE uncertainty (2)
39- 43 F5.3 arcsec theta [0.2/2] Angular Einstein radius θE (3)
45- 49 F5.3 arcsec e_theta [0.004/0.008]? theta uncertainty (2)
51- 55 F5.3 --- qlens [0.5/1] Axial ratio of the lens
(qlens=blens/alens)
57- 61 F5.3 --- e_qlens [0.006/0.2]? qlens uncertainty (2)
63- 65 I3 deg phi [0/176] Position angle of the lens (φlens)
67- 68 I2 deg e_phi [7/19]? phi uncertainty (2)
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Note (1): The position of the lens on the sky relative to the arbitrarily
chosen "image center" based on the ALMA 870um emission.
See section 3.1.
Note (2): Parameters without uncertainties were fixed to the given value.
Note (3): The mass of the lens (parameterized in terms of the angular Einstein
radius, θE).
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 11 A11 --- Name Short ALMA name
13- 18 F6.3 arcsec oRA [-4.9/7.7] Right ascension offset (1)
20- 24 F5.3 arcsec e_oRA [0.003/0.3]? oRA uncertainty
26- 31 F6.3 arcsec oDE [-7.3/4.7] Declination offset (1)
33- 37 F5.3 arcsec e_oDE [0.003/0.3]? oDE uncertainty
39- 43 F5.2 mJy S870 [0.8/17.6] Total intrinsic 870um flux density
45- 48 F4.2 mJy e_S870 [0.01/1.4] S870 uncertainty
50- 54 F5.3 arcsec rs [0.01/0.5] Effective radius length (2)
56- 60 F5.3 arcsec e_rs [0.003/0.3] rs uncertainty
62- 65 F4.2 --- qs [0.2/0.9] Axial ratio (qs=bs/as)
67- 70 F4.2 --- e_qs [0/0.3] qs uncertainty
72- 74 I3 deg phi [-25/178] Position angle (φs);
degrees east of north
76- 77 I2 deg e_phi [1/65] phi uncertainty
79- 83 F5.2 --- mu870 [0/27.2]? Magnification factor
at 870um (µ870)
85- 88 F4.2 --- e_mu870 [0.03/4.7]? mu870 uncertainty
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Note (1): The position of the source (relative to the primary lens if a lens
is present, Δαs and Δδs).
Note (2): rs=(asbs)0.5
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 02-Feb-2016