J/A+AS/129/583 Hubble Deep Field surface photometry (Fasano+ 1998)
Surface photometry of early-type galaxies in the Hubble Deep Field
Fasano G., Filippi M., Bertola F.
<Astron. Astrophys. Suppl. Ser. 129, 583 (1998)>
=1998A&AS..129..583F 1998A&AS..129..583F (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies, photometry ; Photometry, surface
Mission_Name: HST
Keywords: galaxies : elliptical and lenticular,
galaxies: fundamental parameters, galaxies: photometry
Abstract:
The detailed surface photometry of a sample of early-type galaxies in
the Hubble Deep Field is presented as part of a long-term project aimed
to settle strong observational constraints to the theories modelling the
evolution of elliptical galaxies from the early stages.
The sample has been extracted, in the V606 band, from the database
provided by the ESO-STECF-HDF Group (Couch, 1996,
http://ecf.hq.eso.org). The selection criteria involve the total
magnitude, the number of pixels detected above the background level
and an automatic star/galaxy classifier. Moreover, form visual
inspection of the frames, we excluded the galaxies showing unambiguous
late-type morphology. The analysis of the luminosity and geometrical
profiles, carried out on the 162 candidates obeying our selection
criteria, resulted in a list of 99 'bona fide' early-type galaxies,
for which accurate total magnitudes and effective radii were computed
on the basis of the equivalent luminosity profiles. The comparison
with the magnitudes given by Williams et al. (1996,
Cat. J/AJ/112/1335) indicates that the automated photometry tends to
underestimate the total luminosity of the ellipticals. The luminosity
profiles of most of galaxies in our sample follow fairly well the
de∼Vaucouleurs law ('Normal' profiles). However, a relevant fraction
of galaxies, even following the r1/4 law in the main body light
distribution, exhibit in the inner region a flattening of the
luminosity profile not attributable to the PSF (`Flat' profiles) or,
in some cases, a complex (multi-nucleus) structure (`Merger'
profiles). A statistically significant correlation is found between
the shapes of the luminosity profiles and the ellipticity
distribution. In particular, the average ellipticity of galaxies
belonging to the `Flat' and `Merger' classes is significantly higher
than that of the `Normal' galaxies. Finally, even taken into account
the relevant uncertainty of the outer position angle profiles, the
amount of isophotal twisting of HDF ellipticals turns out to be
significantly larger with respect to that of the local samples.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
name.dat 50 99 List of the 99 galaxies in the sample
table1.dat 140 2674 Galaxy parameters
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See also:
J/AJ/112/1335 : Hubble Deep Field observations (Williams+ 1996)
Byte-by-byte Description of file: name.dat
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Bytes Format Units Label Explanations
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1- 10 A10 --- Name Galaxy name
12- 13 I2 h RAh Right ascension (J2000.0)
15- 16 I2 min RAm Right ascension (J2000.0)
18- 21 F4.1 s RAs Right ascension (J2000.0)
23 A1 --- DE- Declination sign
24- 25 I2 deg DEd Declination (J2000.0)
27- 28 I2 arcmin DEm Declination (J2000.0)
30- 31 I2 arcsec DEs Declination (J2000.0)
33- 50 A18 --- WBD96 Simbad denomination ([WBD96] N-NNN.nnnn)
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Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 10 A10 --- Name Galaxy name
12- 17 F6.3 mag/arcsec2 mag V_606 surface brightness (ST system)
19- 25 F7.2 pix Xpos X coord. of the center
27- 33 F7.2 pix Ypos Y coord. of the center
36- 40 F5.2 arcsec Radius Radius along the major axis
42- 47 F6.4 --- Eps Ellipticity = 1-b/a
49- 54 F6.1 deg PA [-211/165] Position Angle from N to W
56- 61 F6.2 0.1 Sin3 ?=99.00 {3[theta] term in Fourier
expansion}*10 (1)
63- 68 F6.2 0.1 Cos3 ?=99.00 {3[theta] term in Fourier
expansion}*10 (1)
70- 75 F6.2 0.1 Sin4 ?=99.00 {4[theta] term in Fourier
expansion}*10 (1)
77- 82 F6.2 0.1 Cos4 ?=99.00 {4[theta] term in Fourier
expansion}*10 (1)
84- 88 F5.3 --- e_Eps Estimated error of the ellipticity
90- 95 F6.2 deg e_PA Estimated error of the position angle
97-104 E8.2 0.1 e_Sin3 Estimated error of Sin3
106-113 E8.2 0.1 e_Cos3 Estimated error of Cos3
115-122 E8.2 0.1 e_Sin4 Estimated error of Sin4
124-131 E8.2 0.1 e_Cos4 Estimated error of Cos4
133-140 E8.2 mag/arcsec2 e_mag Estimated error of surface brightness
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Note (1): 99.00 --> data are not available
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Acknowledgements: Gianni Fasano
(End) Patricia Bauer [CDS] 11-Dec-1997