J/ApJ/743/123 Motions of galaxies in Coma I cloud (Karachentsev+, 2011)
Fast motions of galaxies in the Coma I cloud: a case of dark attractor?
Karachentsev I.D., Nasonova O.G., Courtois H.M.
<Astrophys. J., 743, 123 (2011)>
=2011ApJ...743..123K 2011ApJ...743..123K
ADC_Keywords: Galaxies, nearby ; Clusters, galaxy
Keywords: cosmology: observations - galaxies: clusters: individual: Coma I -
galaxies: distances and redshifts
Abstract:
We note that nearby galaxies having high negative peculiar velocities
are distributed over the sky very inhomogeneously. A part of this
anisotropy is caused by the "Local Velocity Anomaly," i.e., by the
bulk motion of nearby galaxies away from the Local Void. However, half
of the fast-flying objects reside within a small region
[RA=11.5h-13.0h, DE=+20°-40°] known as the Coma I cloud.
According to Makarov & Karachentsev, this complex contains 8 groups, 5
triplets, 10 pairs, and 83 single galaxies with a total mass of
4.7x1013M☉. We use 122 galaxies in the Coma I region with
known distances and radial velocities VLG<3000km/s to draw the
Hubble relation for them. The Hubble diagram shows a Z-shaped effect
of infall with an amplitude of +200km/s on the nearby side and
-700km/s on the back side. This phenomenon can be understood as the
galaxy infall toward a dark attractor with a mass of ∼2x1014M☉
situated at a distance of 15 Mpc from us. The existence of a large
void between the Coma and Virgo clusters also probably affects the
Hubble flow around the Coma I.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 74 36 List of 36 Galaxies with VLG<600km/s and
D>12Mpc (Outside the Virgo Cluster Core)
table2.dat 66 87 MK-Groups with VLG<3000km/s within
RA=[11.5h,13.0h], DE=[+20°,+40°]
table3.dat 53 35 MK-Triplets and Pairs with VLG<3000km/s within
RA=[11.5h,13.0h], DE=[+20°,+40°]
table4.dat 53 83 Field Galaxies within RA=[11.5h,13.0h],
DE=[+20°,+40°], VLG<3000km/s
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See also:
J/MNRAS/412/2498 : Galaxy groups and clouds in local universe (Makarov+, 2011)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 11 A11 --- Gal Galaxy name
13- 14 I2 h RAh Right ascension (J2000)
15- 16 I2 min RAm Right ascension (J2000)
17- 20 F4.1 s RAs Right ascension (J2000)
21 A1 --- DE- Declination sign (J2000)
22- 23 I2 deg DEd Declination (J2000)
24- 25 I2 arcmin DEm Declination (J2000)
26- 27 I2 arcsec DEs [0/60] Declination (J2000)
29- 30 I2 --- TT Morphological T Type
32- 34 I3 km/s VLG Radial velocity relative to the centroid of
the Local Group
36- 39 F4.1 Mpc Dist Distance estimate
41- 43 A3 --- n_Dist Method used for distance measurement (G1)
45- 49 F5.2 mag Btmag Apparent B-band magnitude
51- 53 I3 km/s 2Vm ?=- Doubled amplitude of rotation velocity
55- 59 I5 km/s Vpec Peculiar velocity (VLG-73*Dist)
61- 74 A14 --- Notes Comments on probable galaxy membership
in certain groups
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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- 11 A11 --- Group Group name (1)
13- 25 A13 --- Gal Galaxy name
27 A1 --- --- [J]
28- 29 I2 h RAh Right ascension (J2000)
30- 31 I2 min RAm Right ascension (J2000)
32- 35 F4.1 s RAs Right ascension (J2000)
36 A1 --- DE- Declination sign (J2000)
37- 38 I2 deg DEd Declination (J2000)
39- 40 I2 arcmin DEm Declination (J2000)
41- 42 I2 arcsec DEs Declination (J2000)
44- 47 I4 km/s VLG Radial velocity relative to the centroid of
the Local Group
49- 50 I2 --- TT Morphological T Type
52- 56 F5.2 mag Ksmag 2MASS Ks magnitude
58- 62 F5.2 Mpc Dist ?=- Distance estimate
64- 66 A3 --- n_Dist Method used for distance measurement (G1)
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Note (1): In original table N3990 is a misprint for N3900 (corrected by CDS).
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Byte-by-byte Description of file: table3.dat table4.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 13 A13 --- Gal Galaxy name
14 A1 --- --- [J]
15- 16 I2 h RAh Right ascension (J2000)
17- 18 I2 min RAm Right ascension (J2000)
19- 22 F4.1 s RAs Right ascension (J2000)
23 A1 --- DE- Declination sign (J2000)
24- 25 I2 deg DEd Declination (J2000)
26- 27 I2 arcmin DEm Declination (J2000)
28- 29 I2 arcsec DEs Declination (J2000)
31- 34 I4 km/s VLG Radial velocity relative to the centroid of
the Local Group
36- 37 I2 --- TT Morphological T Type
39- 43 F5.2 mag Ksmag 2MASS Ks magnitude
45- 49 F5.2 Mpc Dist ?=- Distance estimate
51- 53 A3 --- n_Dist Method used for distance measurement (G1)
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Global notes:
Note (G1): Method used for distance measurement as follows:
tf = based on the Tully-Fisher relation with the parameters from
Tully et al. (2008, Cat. J/ApJ/676/184)
sbf = based on the surface brightness fluctuations from Tonry et al.
(2001ApJ...546..681T 2001ApJ...546..681T)
bs = based on the luminosity of the brightest stars
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 06-Oct-2014