J/A+A/382/513 Galaxy warps in the HDF North and South (Reshetnikov+, 2002)
Statistics of galaxy warps in the HDF North and South.
Reshetnikov V., Battaner E., Combes F., Jimenez-Vicente J.
<Astron. Astrophys. 382, 513 (2002)>
=2002A&A...382..513R 2002A&A...382..513R
ADC_Keywords: Galaxies, photometry ; Morphology ; Redshifts
Keywords: galaxies: evolution - galaxies: formation -
general; interactions; peculiar; photometry
Abstract:
We present a statistical study of the presence of galaxy warps in the
Hubble deep fields. Among a complete sample of 45 edge-on galaxies
above a diameter of 1.3", we find 5 galaxies to be certainly warped
and 6 galaxies as good candidates. In addition, 4 galaxies reveal a
characteristic U-warp. Compared to statistical studies of local warps,
and taking into account the strong bias against observing the outer
parts of galaxies at high redshift, these numbers point towards a very
high frequency of warps at z∼1: almost all galaxy discs might be
warped. Furthermore, the amplitude of warps are stronger than for
local warps. This is easily interpreted in terms of higher galaxy
interactions and matter accretion in the past. This result supports
these two mechanisms as the best candidates for the origin of early
warps. The mean observed axis ratio of our sample of edge-on galaxies
is significantly larger in the high-z sample than is found for samples
of local spiral galaxies. This might be due to disk thickening due to
more frequent galaxy interactions.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 88 32 Edge-on galaxies in the HDF-N
table2.dat 62 18 Edge-on galaxies in the HDF-S
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See also:
J/ApJ/513/34 : HDF photometric redshifts catalog (Fernandez-Soto+, 1999)
J/AJ/120/2206 : NTT, HDF-S and HDF-N photometric redshifts (Fontana+, 2000)
J/ApJ/538/29 : HDF-N Caltech faint galaxy redshift survey. X. (Cohen+, 2000)
J/ApJ/538/493 : HDF-South NICMOS field (Yahata+, 2000)
J/ApJS/127/1 : UGRK Photometry in the Hubble Deep field region (Hogg+, 2000)
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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- 4 I4 --- [FLY99] Number according to the catalogue of
Fernandez-Soto et al., 1999, Cat. J/ApJ/513/34
6- 11 F6.1 pix Xpos X position
13- 18 F6.1 pix Ypos Y position
20- 29 A10 --- [WBD96] Williams et al. (1996, Cat. J/AJ/112/1335)
identification number
31- 35 F5.2 mag Imag I814 magnitude in AB photometric system
37- 41 F5.3 --- z ? Spectroscopic redshift
(Cohen et al. 2000, Cat. J/ApJ/538/29;
Hogg et al. 2000, Cat. J/ApJS/127/1)
43- 47 F5.3 --- z1 Photometric redshift from Fernandez-Soto et al.
(1999, Cat. J/ApJ/513/34)
49- 52 F4.2 --- z2 Photometric redshift according to Fontana et al.
(2000, Cat. J/AJ/120/2206)
54- 56 A3 --- Type Best-fit spectral type of galaxy,
Fernandez-Soto et al. 1999, Cat. J/ApJ/513/34
58 A1 --- Warp [456U] Index of warp (G1)
64- 65 I2 h RAh Right Ascension J2000 (hours) (1)
67- 68 I2 min RAm Right Ascension J2000 (minutes) (1)
70- 75 F6.3 s RAs Right Ascension J2000 (seconds) (1)
77 A1 --- DE- Declination J2000 (sign) (1)
78- 79 I2 deg DEd Declination J2000 (degrees) (1)
81- 82 I2 arcmin DEm Declination J2000 (minutes) (1)
84- 88 F5.2 arcsec DEs Declination J2000 (seconds) (1)
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Note (1): position from Fernandez-Soto et al., 1999, Cat. J/ApJ/513/34
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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 Name according to the Stony Brook catalogue,
(Yahata et al., 2000ApJ...538..493Y 2000ApJ...538..493Y) (1)
17- 21 F5.2 mag Imag I814 magnitude in AB photometric system
23- 26 F4.2 --- z1 Photometric redshift from Fernandez-Soto
et al. 1999, Cat. J/ApJ/513/34
28- 31 F4.2 --- z2 Photometric redshift according to Fontana et al.
(2000, Cat. J/AJ/120/2206)
33- 35 A3 --- Type Best-fit spectral type of galaxy
(Fernandez-Soto et al. 1999, Cat. J/ApJ/513/34)
37 I1 --- Warp [4-6]? Index of warp (G1)
39- 40 I2 h RAh Right Ascension J2000 (hours) (2)
42- 43 I2 min RAm Right Ascension J2000 (minutes) (2)
45- 49 F5.2 s RAs Right Ascension J2000 (seconds) (2)
51 A1 --- DE- Declination J2000 (sign) (2)
52- 53 I2 deg DEd Declination J2000 (degrees) (2)
55- 56 I2 arcmin DEm Declination J2000 (minutes) (2)
58- 62 F5.2 arcsec DEs Declination J2000 (seconds) (2)
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Note (1): The numbers mean coordinates in pixels
Note (2): The position is taken from the Stony Brook catalogue
(2000ApJ...538..493Y 2000ApJ...538..493Y)
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Global notes:
Note (G1): Index of warp:
The original I814-band images and contour maps of all the sample
galaxies were examined independently by three of us (E.B., F.C. and
V.R.). On the basis of eyeball classification, they assigned an "index
of warp" (IW) for each object:
0 - no warp,
2 - a certain integral-shaped warp, and
1 - intermediate case.
We also marked U-shaped warps, when the plane bends towards the same
direction on both sides (Reshetnikov & Combes, 1998A&A...337....9R 1998A&A...337....9R)
like the letter "U". Then, we summed the personal indices for each
object and decided to consider those galaxies with total IW=6 (index 2
for each observer) as true warps and IW=4-5 as good candidates for
warped disks. So:
6: a certain integral-shaped warp
4,5: good candidates to be warped
U: U-shaped warps
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History:
From electronic version of the journal
* 10-Jul-2002: added the positions in tables 1 and 2.
(End) Patricia Bauer [CDS] 15-Mar-2002