J/ApJ/888/92 Star-forming clumps in local luminous IR galaxies (Larson+, 2020)
Star-forming clumps in local luminous infrared galaxies.
Larson K.L., Diaz-Santos T., Armus L., Privon G.C., Linden S.T., Evans A.S.,
Howell J., Charmandaris V., U. V, Sanders D.B., Stierwalt S.,
Barcos-Munoz L., Rich J., Medling A., Cook D., Oklopcic A., Murphy E.J.,
Bonfini P.
<Astrophys. J., 888, 92 (2020)>
=2020ApJ...888...92L 2020ApJ...888...92L
ADC_Keywords: Galaxies, IR; Star Forming Region; Surveys
Keywords: Interacting galaxies; Star-forming regions; Luminous infrared galaxies
Abstract:
We present HST narrowband near-infrared imaging of Paα and
Paβ emission of 48 local luminous infrared galaxies (LIRGs) from
the Great Observatories All-Sky LIRG Survey. These data allow us to
measure the properties of 810 spatially resolved star-forming regions
(59 nuclei and 751 extranuclear clumps) and directly compare their
properties to those found in both local and high-redshift star-forming
galaxies. We find that in LIRGs the star-forming clumps have radii
ranging from ∼90 to 900pc and star formation rates (SFRs) of
∼1x10-3 to 10M☉/yr, with median values for extranuclear clumps
of 170pc and 0.03M☉/yr. The detected star-forming clumps are
young, with a median stellar age of 8.7Myr, and have a median stellar
mass of 5x105M☉. The SFRs span the range of those found in
normal local star-forming galaxies to those found in high-redshift
star-forming galaxies at z=1-3. The luminosity function of the LIRG
clumps has a flatter slope than found in lower-luminosity,
star-forming galaxies, indicating a relative excess of luminous
star-forming clumps. In order to predict the possible range of
star-forming histories and gas fractions, we compare the star-forming
clumps to those measured in the MassiveFIRE high-resolution
cosmological simulation. The star-forming clumps in MassiveFIRE cover
the same range of SFRs and sizes found in the local LIRGs and have
total gas fractions that extend from 10% to 90%. If local LIRGs are
similar to these simulated galaxies, we expect that future
observations with ALMA will find a large range of gas fractions, and
corresponding star formation efficiencies, among the star-forming
clumps in LIRGs.
Description:
The Great Observatories All-Sky LIRG Survey (GOALS;
Armus+ 2009PASP..121..559A 2009PASP..121..559A) is a complete galaxy sample that comprises
the 201 LIRG systems (z<0.088) included in the IRAS Revised Bright
Galaxy Sample (Sanders+ 2003, J/AJ/126/1607).
Here we present and analyze Paα and Paβ HST images of a
sample of 48 LIRGs in GOALS with LIR values that range from 1011.2 to
1012.3. The Paα data (27 systems) are HST archival images from
PID 10169.
The Paβ observations were taken with the HST WFC3 camera (Project
ID: 13690; PI: T. Diaz-Santos), which has a plate scale of 0.12"/pixel
using the F130N and F132N narrowband filters and the F110W broadband
filter. The total integration times were 120s for each broadband
filter and about 1100s (19min) for each narrowband filter. The 2' FOV
of WFC3-IR allows for galaxies in a pair to be observed simultaneously.
The archival Paα observations were taken with the HST NIC2
camera, which has a plate scale of 0.076"/pixel and a 19.2" FOV using
the F187N and F190N narrowband filters.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 75 48 Observations
table3.dat 78 765 Properties of star-forming clumps in GOALS galaxies
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See also:
B/hst : HST Archived Exposures Catalog (STScI, 2007)
J/ApJ/428/693 : Rosette Nebula & Maddalena Cloud structures (Williams+ 1994)
J/AJ/126/1607 : IRAS Revised Bright Galaxy Sample (Sanders+, 2003)
J/AJ/136/2782 : Star formation efficiency in nearby galaxies (Leroy+, 2008)
J/ApJ/741/32 : Spatial extent of (U)LIRGs in MIR. II. (Diaz-Santos+, 2011)
J/A+A/533/A119 : GOODS-Herschel North and South catalogs (Elbaz+, 2011)
J/ApJS/206/1 : Mid-IR properties of GOALS nearby LIRGs (Stierwalt+, 2013)
J/ApJ/774/68 : [CII]157.7um feature in LIRGs (Diaz-Santos+, 2013)
J/ApJ/790/124 : Dust and gas physics of the GOALS sample (Stierwalt+, 2014)
J/MNRAS/462/3766 : List of galaxies with star forming regions (Cook+, 2016)
J/A+A/590/A67 : Ionized gas maps of local U/LIRGs (Piqueras-Lopez+, 2016)
J/ApJ/846/32 : Herschel FIR spectra of GOALS galaxies (Diaz-Santos+, 2017)
J/ApJ/853/108 : Clumpy galaxies in CANDELS. II. 0.5≤z<3.0 (Guo+, 2018)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 16 A16 --- Gal Galaxy name(s)
18- 21 A4 --- --- [IRAS]
23- 33 A11 --- IRAS IRAS name (FHHMMm+DDMM, B1950 or
HHMMm+DDMM, B1950)
35- 42 F8.6 --- z [0.0093/0.035] Redshift
44- 55 A12 --- Filt Filters
57- 61 I5 --- PID [10169/13690] Program ID
63- 75 A13 --- AName Abbreviated name as used in Table 3;
column added by CDS
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 13 A13 --- AName Galaxy/IRAS abbreviated name
14 A1 --- --- [_]
15- 17 A3 --- Clump Clump name within AName
19- 25 F7.5 Msun/yr SFR [0.0022/9.6] Clump Star Formation Rate
27- 32 F6.4 Msun/yr e_SFR [0.0001/1] SFR error
34- 41 E8.3 yr Age [1.5e+6/1.9e+10]? Clump age
43- 49 E7.2 yr e_Age [100000/1.5e+10]? Clump age error
51- 60 E10.5 Msun Mass [13150/3.9e+10]? Clump mass
62- 68 E7.2 Msun e_Mass [6.5/2.8e+9]? Clump mass error
70- 70 A1 --- l_Rad Upper limit flag on Rad
72- 74 I3 pc Rad [88/882] Effective radius of the clumps
76- 78 I3 pc e_Rad [2/267] Effective radius error
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 22-Jun-2021