J/A+A/406/75 JHKs magnitudes of variables in NGC 5128 (Rejkuba+, 2003)
Long period variables in NGC 5128. I. Catalogue.
Rejkuba M., Minniti D., Silva D.R.
<Astron. Astrophys. 406, 75 (2003)>
=2003A&A...406...75R 2003A&A...406...75R
ADC_Keywords: Galaxies, photometry ; Stars, variable ; Photometry, infrared
Keywords: galaxies: elliptical and lenticular, cD - galaxies: stellar content -
stars: variables: general - stars: AGB and post-AGB -
galaxies: individual: NGC 5128
Abstract:
The first variable star catalogue in a giant elliptical galaxy
NGC 5128 (Centaurus A) is presented. Using multi-epoch observations
with ISAAC at the VLT we have detected 1504 red variables in two halo
fields covering 10.46-arcmin square. For the variables with at least 10
good measurements, periods and amplitudes were determined using
Fourier analysis and non-linear sine-curve fitting algorithms. The
final catalogue contains 1146 long period variables with well
established light curve parameters. Periods, amplitudes, JsHKs
photometry as well as individual KS-band magnitudes are provided for
all the variables. The distribution of amplitudes ranges from 0.3 to a
few magnitudes in the Ks-band, with a median value around 0.7mag. The
amplitudes, mean magnitudes and periods indicate that the majority of
variables belong to the class of long period variables with
semiregular and Mira variables. Exhaustive simulations were performed
in order to assess the completeness of our catalogue and the accuracy
of the derived periods.
Description:
We have obtained a total of 20 epochs of Ks-band photometry in Field 1
and 24 epochs in Field 2 between April 1999 and July 2002. Most of our
data were obtained using the ISAAC near-IR imaging spectrometer at the
ESO Paranal UT1 Antu 8.2m telescope. These data were obtained in
Service Mode. One Field 2 epoch comes from data obtained in Visitor
Mode at the ESO La Silla NTT 3.5m telescope equipped with SOFI
near-IR imaging spectrometer.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 39 48 Near-IR multi-epoch photometry observing log
table2.dat 72 40 Data for a sample of variables with light curves
plotted in Fig. 5
table3.dat 72 437 LPVs in Field 1
table4.dat 72 709 LPVs in Field 2
table5.dat 72 163 Additional variable stars in Field 1 for which
periods could not be determined
table6.dat 72 194 Additional variable stars in Field 2 for which
periods could not be determined
table7.dat 41 12020 Individual measurements of the K-band magnitudes
for the 3 red variable stars detected in Field 1
table8.dat 41 21672 Individual measurements of the K-band magnitudes
for the 3 red variable stars detected in Field 2
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See also:
J/A+A/369/812 : UVKs photometry of globular clusters in NGC 5128 (Rejkuba 2001)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 2 A2 --- Field Field (F1 or F2)
4- 12 F9.1 d JD Julian date
15- 16 I2 min Exp Exposure time
19- 22 F4.2 --- X Mean airmass during the observing sequence
25- 28 F4.2 arcsec Seeing Seeing
31- 35 A5 --- FilEp Filter epoch
37 I1 ---- Instr [1/2]? Instrument (1)
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Note (1): the codes are as follows:
1 = Observed with SOFI at NTT.
2 = Observed with LW arm of ISAAC at VLT.
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Byte-by-byte Description of file: table[2-6].dat
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Bytes Format Units Label Explanations
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1- 8 A8 --- [RMS2003] Identification, FN NNNNN
10- 16 F7.3 pix xpos x position with respect to the
reference epoch (G1)
18- 24 F7.3 pix ypos y position with respect to the
reference epoch (G1)
26- 30 A5 --- FilEp Reference epoch, defined in table1.dat
32- 35 I4 d Per ? Best fitting period
37- 41 F5.3 mag A ? Semi-amplitude
43- 48 F6.2 --- chi2 ? Reduced chi2 of the sine-curve fit
50- 54 F5.3 --- signif ? Significance of the period from
Fourier analysis
56- 60 F5.2 mag Jsmag ?=99.99 Single epoch Js-band magnitude (1)
62- 66 F5.2 mag Hmag ?=99.99 Single epoch H-band magnitude (1)
68- 72 F5.2 mag <Ks>mag Mean Ks-band magnitude from the sine-curve fit
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Note (1): Magnitude 99.99 denotes that no measurement for that star was obtained
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Byte-by-byte Description of file: table7.dat table8.dat
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Bytes Format Units Label Explanations
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1- 8 A8 --- [RMS2003] Identification, FN NNNN
10- 16 F7.3 pix xpos x position (G1) (1)
18- 24 F7.3 pix ypos y position (G1) (1)
26- 30 A5 --- FilEp Filter epoch
32- 36 F5.2 mag Kmag ?=99.99 Filter epoch K-band magnitude (2)
38- 41 F4.2 mag e_Kmag ?=9.99 rms uncertainty on Kmag (2)
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Note (1): Positions with respect to the reference epoch,
1Ks07 for table7.dat (Field 1), 2Ks10 for table8.dat (Field 2)
Note (2): Individual K-band magnitudes and the errors of the measurements
as given by ALLFRAME to which 0.04 mag calibration error have been
added in quadrature.
Magnitude 99.99 and the error 9.99 denote that no measurement for
that star was obtained.
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Global notes:
Note (G1): x, y coordinates:
1 pix = 0.1478"
Field 1: (1, 1) = (13h 26m 17.5s, -42° 51' 03.3") (J2000.0)
Field 2: (1, 1) = (13h 25m 18.0s, -43° 09' 03.0") (J2000.0)
Negative numbers for x and y positions mean that the star was
out of the limits of the reference frame.
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History:
From electronic version of the journal.
Complete tables were added on 10-Dec-2004
(End) James Marcout, Patricia Bauer [CDS] 10-Dec-2004