J/AN/325/307 UBVIc photometry of NGC 3077 center (Notni+, 2004)
The central region of NGC 3077: ground-based photometry and age of
bright `starlike' objects.
Notni P., Karachentsev I.D., Makarova L.N.
<Astron. Nachr., 325, 307-316 (2004)>
=2004AN....325..307N 2004AN....325..307N
ADC_Keywords: Galaxies, photometry ; Photometry, UBVRI ; Photometry, Cousins
Keywords: galaxies: dwarfs (NGC 3077) - galaxies: stellar photometry -
galaxies: stellar content
Abstract:
We present UBVIc photometry of starlike objects in the central region
of NGC 3077. The colour-colour and colour-magnitude diagrams of the
objects are discussed. Many of the objects under consideration,
starlike from the ground, are probably dense young star clusters
(super star clusters, SSC). Ages spreading over ∼4 to ∼150Myr are
estimated for most of these objects. Sakai and Madore
(2001ApJ...555..280S 2001ApJ...555..280S) found enhanced star formation ∼30-125Myr ago
also in the halo of this galaxy; thus, high star forming activity has
occurred within the entire galaxy (centre and halo) since
∼130..150Myr. Having ended in the outer regions about 30Myr ago, it is
going on near the centre with full vigour.
Description:
CCD images of NGC 3077 were obtained in 3 runs: at the primary focus
of the 6m-telescope of the Special Astrophysical Observatory (Russian
Academy of Sciences) in 1993 and 1006, and an additional one at the
1.23m-telescope of the German-Spanish Observatory on Calar Alto, in
1995. Two frames were taken in each band in each run.
Objects:
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RA (2000) DE Designation(s)
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10 03 20.0 +68 44 02 NGC 3077 = UGC 5398
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 77 124 UBVIc photometry of bright starlike objects
in NGC 3077
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Table 1: Log of observations.
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Date Observatory CCD Scale Field Filter Seeing radius
Telescope pixel arcsec/pix arcsec FWHM," arcsec
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1993 SAO 6m 520x 580 0.15x0.20 80x120 VI 1.2 1.0
1993 SAO 6m 520x 580 0.274 140x160 BVI 1.5 1.4
1995 CA 1.23m 960x1024 0.5 480x512 UBVI 1.4 2.0
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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- 3 I3 --- [NKM2004] [1/124] Sequential number
5- 10 F6.1 pix Xpos X position (1)
12- 17 F6.1 pix Ypos Y position (1)
19- 23 F5.1 s oRA Offset in right ascension (2)
25- 27 I3 arcsec oDE Offset in declination (2)
29- 31 I3 arcsec R Distance from dynamical centre at
X=224.6,Y=107.7 (Price & Gullixson,
1989ApJ...337..658P 1989ApJ...337..658P)
33- 37 F5.2 mag Vmag V magnitude
39- 43 F5.2 mag B-V ?=- B-V colour index
45- 49 F5.2 mag V-Ic ?=- V-Ic colour index
51- 55 F5.2 mag U-B ?=- U-B colour index
57- 58 I2 --- qB ?=- Quality measure on B band
60- 61 I2 --- qV ?=- Quality measure on V band
63- 64 I2 --- qIc ?=- Quality measure on Ic band
66- 67 I2 --- qU ?=- Quality measure on U band
69- 70 A2 --- Frame [ca CA --] Frame (3)
72 A1 --- [BBD74] [a-m] Designation by Barbieri et al.,
1974A&A....35..463B 1974A&A....35..463B, [BBD74] Blue a in Simbad
75- 77 A3 --- MType Morphology from HST frame (5)
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Note (1): X, Y rectangular coordinates on SAO 1996 frame, in pixel,
1 pix = 0.274 arcsec, X points to p.a. 26.4deg, Y to 116.4
Note (2): Equatorial coordinates, referred to
RA=10h02min, DE=+68°40' (2000)
Note (3): Frames as follows:
CA = measurement on Calar Alto frames only
ca = Calar Alto measurement included
Note (5): Morphology from HST frame as follows:
s = single (dominant) star
2s = 2 dominant stars
sd = diffuse star
sdg = diffuse star in group
sgr = dominant star in (loose) group
scl = dominant star in a `cloud'
gr = group of stars of comparable brightness
cl = stellar cloud (very loose group)
gc = concentrated group or Super star cluster
d = diffuse
- = unconspicious fluctuation
gal = background galaxy
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 16-Sep-2005