B/avo.rad MERLIN+VLA images of HDF/HFF sources (Muxlow+, 2003)
High Resolution Images of Radio Sources in the Hubble Deep and Flanking Fields
Muxlow T.W.B, Richards A.M.S, Garrington S.T., Wilkinson P.N.
Anderson B.A., Richards E.A., Axon D.J., Partridge R.B.,
Kellermann K.I., Fomalont E.B.
Muxlow T.W.B, et al. MNRAS (in press)
<Mon. Not. R. Astron. Soc. in press (2003)>
=2003MNRAS.(in.press)
ADC_Keywords: Radio sources ; Surveys
Keywords: galaxies: evolution - galaxies: active - galaxies: starburst -
cosmology: observations - radio continuum: galaxies
Abstract:
18 days of MERLIN data and 42 hours of A-array VLA data at 1.4 GHz
have been combined to image a 10 arcminute field centred on the Hubble
Deep Field. This area includes both the Hubble Deep and Flanking
Fields. A complete sample of 92 sources with flux densities above
40µJy have been detected using the VLA data, and imaged with the
MERLIN+VLA combination at resolutions of 0.2, 0.3 and 0.5 arcsecond.
These are the most sensitive 1.4 GHz images yet made, with rms noise
levels of 3.3µJy/beam in the 0.2 arcsecond images. Virtually all
the objects are resolved by the MERLIN+VLA combination images showing
that they have angular sizes in the range 0.2 to 3 arcseconds,
typically smaller than the sizes of the optical galaxy images. In
addition to the imaging of 92 sources found with the VLA alone, the
central 3 arcminutes, which encloses the HDF, has been separately
imaged with the MERLIN+VLA combination at the full 3.3µJy/beam
sensitivity to search for compact sources fainter than 40µJy. No
additional sources were found that were not previously detected by the
VLA, indicating that such sources are heavily resolved with MERLIN and
hence must have typical angular sizes >0.5 arcseconds. In addition to
the images, high quality astrometry is an equally important product of
this work allowing reliable source identification in a crowded field.
Radio sources associated with compact galaxies have been used to align
both the HST WFPC2 frames and a CFHT optical field to the ICRF. The
HST optical field has been aligned to better than 50 mas in the Deep
Field itself, and to ∼150 mas in the outer parts of the Flanking
Fields. The proportion of starburst systems is found to increase with
decreasing source strength. At fluxes below 100µJy in excess of 70%
of the µJy sources are found to be starburst type systems
associated with major disc galaxies in the redshift range 0.3 - 1.3.
Some 40% of the brighter sources are found to be intermediate
luminosity AGN systems identified with galxies in a similar redshift
range. Around 85% of the sources are identified with galaxies brighter
than I=25mag. The remaining 15% are associated with optically faint
systems close to or beyond the HDF limit; many of these may be
dust-shrouded starburst galaxies at high redshift (z>3). Approaching
half the sources in the 10 arcminute field are detected in X-rays by
the Chandra Satellite. The X-ray detection rate appears to be
uncorrelated with the radio source classification.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
catalog.dat 200 92 MERLIN+VLA HFF/HDF(N) catalogue
vla.dat 72 92 VLA data
wsrt.dat 77 92 WSRT data
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See also:
ftp://ftp.jb.man.ac.uk/pub/merlin/AVODEMO/hdfmnras11.ps : Draft of
Muxlow et al. 2003
ftp://ftp.jb.man.ac.uk/pub/merlin/AVODEMO/hdfmnras2_new_table.ps : table
ftp://ftp.jb.man.ac.uk/pub/merlin/AVODEMO/starpic.ps : colour figure
Byte-by-byte Description of file: catalog.dat
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Bytes Format Units Label Explanations
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1- 14 A14 --- Name Designation of the source
16- 17 I2 h RAh Hour of Right Ascension (J2000)
19- 20 I2 min RAm Minute of Right Ascension (J2000)
22- 28 F7.4 s RAs Second of Right Ascension (J2000)
30- 32 I3 mas e_RAs Relative position error in Right Ascension (1)
34 A1 --- DE- Sign of Declination (J2000)
35- 36 I2 deg DEd Degree of Declination (J2000)
38- 39 I2 arcmin DEm Arcminute of Declination (J2000)
41- 46 F6.3 arcsec DEs Arcsecond of Declination (J2000)
48- 50 I3 mas e_DEs Relative position error in Declination (1)
52- 54 F3.1 arcsec Beam Circular restoring beam diameter in map
used for analysis
56 A1 --- Vpos [V] means low surface brightness extended
source, VLA position given.
58- 61 A4 --- Opt Counterpart is seen in CFHT or HST image (2)
63- 66 I4 uJy Vflux Total flux density in VLA image at 1.4GHz
(2arcsec resolution)
68- 71 I4 uJy e_Vflux Mean error on Vflux
73- 77 F5.2 arcsec LAS Largest angular size
79- 81 I3 --- WSRT ? ID in WSRT catalogue (2000A&A...361L..41G 2000A&A...361L..41G)
83- 86 I4 uJy Wpeak ? Peak WSRT flux density at 1.38GHz
(15arcsec resolution)
88- 91 I4 uJy Wint ? Integrated WSRT flux density
93 A1 --- m_WSRT WSRT flux densities include two sources
with same WSRT ID
95 A1 --- l_Sp-Index Sp-Index is lower limit
96-100 F5.2 --- Sp-Index ? Spectral index between 8.4 and 1.4 GHz
(2000ApJ...533...611R)
102-104 A3 --- Struct Radio structural description (3)
106 A1 --- l_Imag [≳] Imag is approximative or lower limit
107-110 F4.1 mag Imag ? I magnitude from CFHT or HST (2)
112-114 A3 --- X-ray [Yes No] Counterpart is seen in CHANDRA image
(2001AJ....122.2810B 2001AJ....122.2810B)
116-118 A3 --- IR [Yes No] Counterpart is seen in ISO image
(1999A&A...342..313A 1999A&A...342..313A)
120-167 A48 --- Align Radio-optical alignment characteristics
169-172 A4 --- Class Classification of galaxy (4)
174-178 F5.3 --- z ? Redshift
180 A1 --- f_z [SP] Redshift Type: Spectroscopic, Photometric
182-200 A19 --- r_z Bibliographic reference for redshift
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Note (1):
The MERLIN+VLA observations are aligned with the ICRF to within 15mas
Note (2):
CFHT = Canada-France-Hawaii Telescope, 1999AJ....117..102B 1999AJ....117..102B
HST = Hubble Space Telescope, 1996AJ....112.1335W 1996AJ....112.1335W
Note (3): Radio structure:
CE = Compact component with extended emission
C = Compact component
C1E = Compact emission with one-sided extension
E+ = Extended component, some emission only seen at 2arcsec resolution
CE+ = Compact component with some extended emission
only seen at 2arcsec resolution
FR1 = Faranoff-Riley class 1 radio jets/lobes
WAT = Wide Angle Tail (FR1)
Note (4): Classification of galaxy:
Uncl = Unclear
S = Starburst
S+ = Starburst with embedded AGN
SC = Starburst Candidate
SC+ = Starburst Candidate with embedded AGN
AGN = Active Galactic Nucleus
AGNC = AGN Candidate
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Byte-by-byte Description of file: vla.dat
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Bytes Format Units Label Explanations
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1- 14 A14 --- Name Designation of the source
16- 17 I2 h RAh Hour of Right Ascension (J2000)
19- 20 I2 min RAm Minute of Right Ascension (J2000)
22- 28 F7.4 s RAs Second of Right Ascension (J2000)
30- 32 I3 mas e_RAs Relative position error in Right Ascension
34 A1 --- DE- Sign of Declination (J2000)
35- 36 I2 deg DEd Degree of Declination (J2000)
38- 39 I2 arcmin DEm Arcminute of Declination (J2000)
41- 46 F6.3 arcsec DEs Arcsecond of Declination (J2000)
48- 50 I3 mas e_DEs Relative position error in Declination
52- 54 F3.1 arcsec Beam Circular restoring beam diameter in map
used for analysis
56 A1 --- Vpos [V] means low surface brightness extended
source, VLA position given.
58- 61 A4 --- Opt Counterpart is seen in CFHT or HST image
63- 66 I4 uJy Vflux Total flux density in VLA image at 1.4GHz
(2arcsec resolution)
68- 72 F5.2 arcsec LAS Largest angular size
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Byte-by-byte Description of file: wsrt.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 14 A14 --- Name Designation of the source
16- 17 I2 h RAh Hour of Right Ascension (J2000)
19- 20 I2 min RAm Minute of Right Ascension (J2000)
22- 28 F7.4 s RAs Second of Right Ascension (J2000)
30- 32 I3 mas e_RAs Relative position error in Right Ascension
34 A1 --- DE- Sign of Declination (J2000)
35- 36 I2 deg DEd Degree of Declination (J2000)
38- 39 I2 arcmin DEm Arcminute of Declination (J2000)
41- 46 F6.3 arcsec DEs Arcsecond of Declination (J2000)
48- 50 I3 mas e_DEs Relative position error in Declination
52- 54 F3.1 arcsec Beam Circular restoring beam diameter in map
used for analysis
56 A1 --- Vpos [V] means low surface brightness extended
source, VLA position given.
58- 61 A4 --- Opt Counterpart is seen in CFHT or HST image
63- 65 I3 --- WSRT ? ID in WSRT catalogue (2000A&A...361L..41G 2000A&A...361L..41G)
67- 70 I4 uJy Wpeak ? Peak WSRT flux density at 1.38GHz
(15arcsec resolution)
72- 75 I4 uJy Wint ? Integrated WSRT flux density
77 A1 --- m_WSRT WSRT flux densities include two sources
with same WSRT ID
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History:
Prepared by A. Richards
(End) A. Richards [Jodrell Bank] 20-Dec-2002