J/ApJ/378/65 8.4GHz observations of compact starbursts (Condon+ 1991)
Compact starbursts in ultraluminous infrared galaxies.
Condon J.J., Huang Z.-P., Yin Q.F., Thuan T.X.
<Astrophys. J. 378, 65 (1991)>
=1991ApJ...378...65C 1991ApJ...378...65C
ADC_Keywords: Galaxies, IR ; Galaxies, radio
Keywords: galaxies: stellar content - galaxies: structure - infrared : sources -
interferometry - radio sources: galaxies - stars: formation
Abstract:
The 40 ultraluminous (log(LFIR/L☉≥11.25) galaxies in the IRAS
Bright Galaxy Sample of sources stronger than S=5.24Jy at
λ=60µm were mapped with approximately 0.25-arcsec resolution
at 8.44GHz. Twenty-five contain diffuse radio sources obeying the
FIR-radio correlation; these are almost certainly starburst galaxies.
Fourteen other galaxies have nearly blackbody FIR spectra with color
temperatures between 60 and 80K so their (unmeasured) FIR angular
sizes must exceed approximately 0.25-arcsec, yet they contain compact
(but usually resolved) radio sources smaller than this limit. The
unique radio and FIR properties of these galaxies can be modeled by
ultraluminous nuclear starbursts so dense that they are optically
thick to free-free absorption at ν∼1.49GHz and dust absorption at
λ∼25µm. Only one galaxy (UGC 08058 = Mrk 231) is a dominated
by a variable radio source too compact to be an ultraluminous
starburst; it must be powered by a 'monster'.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 65 40 Far-Infrared characteristics of the sample galaxies
table2.dat 98 52 Radio data for the sample galaxies
(N=52 obs. for 40 galaxies)
--------------------------------------------------------------------------------
See also:
J/ApJS/143/315 : IRAS 1Jy sample of ultraluminous galaxies. II (Veilleux+ 2002)
J/ApJS/143/277 : IRAS 1Jy sample of ultraluminous galaxies. I. (Kim+, 2002)
J/ApJS/131/185 : The FIRST sample of ultraluminous IR galaxies (Stanford+ 2000)
J/ApJ/522/113 : 1Jy IRAS galaxies optical spectroscopy (Veilleux+, 1999)
J/A+A/409/115 : VLA imaging of IRAS 1 Jy ULIRG sample (Nagar+, 2003)
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 13 A13 --- Name Galaxy name
16 A1 --- l_S12um Limit flag on S12um
17- 20 F4.2 Jy S12um Flux density at 12µm
22- 26 F5.2 Jy S25um Flux density at 25µm
28- 33 F6.2 Jy S60um Flux density at 60µm
35- 40 F6.2 Jy S100um Flux density at 100µm
42- 45 F4.2 --- C60mu 60µm spectral curvature (1)
48- 52 F5.1 Mpc Dist Distance based on H0=75km/s/Mpc
55- 59 F5.2 [solLum] logLFIR Absolute far-infrared luminosity
61 A1 --- l_Size [~] Limt flag on Size
62- 65 F4.2 arcsec Size ? Angular diameter of a circular blackbody
matching the observed flux densities
at 25, 60 and 100µm.
--------------------------------------------------------------------------------
Note (1): 60µm spectral curvature:
C60um = alpha(25um, 60um) - alpha(60um, 100um),
with alpha the spectral index (-dlog(S)/dlogν)
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 13 A13 --- Name Galaxy name
16- 20 F5.1 mJy S1.49GHz VLA flux density at 1.49GHz
22- 25 F4.2 --- q Logarithmic FIR/radio (1.49GHz) flux-density
ratio
27- 30 F4.2 arcsec FWHMmaj ? FWHM major axis of the Gaussian beam (1)
32- 34 F3.2 arcsec FWHMmin ? FWHM minor axis of the Gaussian beam (1)
36- 40 F5.1 mJy S8.44GHz ? Total flux density at 8.44GHz
41 A1 --- u_S8.44GHz [)] Uncertainty flag on S8.44GHz
42- 46 F5.2 --- Sp-Index ? Spectral index between 1.49 and 8.44GHz
47 A1 --- n_Sp-Index Note on Sp-Index (2)
49- 50 I2 h RAh ? Right ascension (B1950)
52- 53 I2 min RAm ? Right ascension (B1950)
55- 59 F5.2 s RAs ? Right ascension (B1950)
61 A1 --- DE- Declination sign (B1950)
62- 63 I2 deg DEd ? Declination (B1950)
65- 66 I2 arcmin DEm ? Declination (B1950)
68- 71 F4.1 arcsec DEs ? Declination (B1950)
73- 77 F5.1 mJy Sp ? Peak flux density at 8.44GHz
79- 83 F5.1 mJy St ? Integrated flux density at 8.44GHz
85 A1 --- l_FWHMmaj Limit flag on FWHMmaj
86- 89 F4.2 arcsec dFWHMmaj ? Deconvolved FWHM major axis
91- 93 F3.2 arcsec dFWHMmin ? Deconvolved FWHM minor axis
95 A1 --- l_logTb limit flag on logTb
96- 98 F3.1 [K] logTb ? 8.44GHz brightness temperature
--------------------------------------------------------------------------------
Note (1): FWHM major and minor axis of the Gaussian beam used to restore
the 8.44GHz map. The major-axis position angle is always PA=0°.
Note (2): Note in Sp-Index:
): uncertain value
]: value based on flux density measured at 1.49GHz and frequencies
other than 8.44GHz:
NGC 0695: S4.86GHz = 24mJy
NGC 1614: S4.86GHz = 31mJy
NGC 3690: S4.85GHz = 300mJy
NGC 5256: S10.7GHz = 28mJy
UGC 09618: S4.86GHz = 35mJy
NGC 6285/6: S4.85GHz = 53mJy
NGC 7469: S8.1GHz = 58mJy
--------------------------------------------------------------------------------
History:
Prepared via OCR.
Acknowledgements:
From Heinz A. Andernach (R528 in his list)
(End) Patricia Bauer [CDS] 27-Nov-2003