J/AJ/138/1661 The Araucaria Project: RR Lyrae in SMC (Szewczyk+, 2009)
The Araucaria Project: the distance to the Small Magellanic Cloud from
near-infrared photometry of RR Lyrae variables.
Szewczyk O., Pietrzynski G., Gieren W., Ciechanowska A., Bresolin F.,
Kudritzki R.-P.
<Astron. J., 138, 1661-1666 (2009)>
=2009AJ....138.1661S 2009AJ....138.1661S
ADC_Keywords: Magellanic Clouds ; Photometry, infrared ; Stars, variable
Keywords: distance scale - galaxies: distances and redshifts - infrared: stars -
galaxies: individual (SMC) - stars: individual (RR Lyrae)
Abstract:
We have obtained deep infrared J- and K-band observations of nine
4.9x4.9arcmin fields in the Small Magellanic Cloud (SMC) with the ESO
New Technology Telescope equipped with the SOFI infrared camera. In
these fields, 34 RR Lyrae stars cataloged by the OGLE collaboration
were identified. Using different theoretical and empirical
calibrations of the infrared period-luminosity-metallicity relation,
we find consistent SMC distance moduli, and find a best true distance
modulus to the SMC of 18.97±0.03 (statistical) ±0.12 (systematic)
mag, which agrees well with most independent distance determinations
to this galaxy, and puts the SMC 0.39mag more distant than the Large
Magellanic Cloud for which our group has recently derived, from the
same technique, a distance of 18.58mag.
Description:
During several observing runs of the Araucaria Project, we have
obtained all the data analyzed and presented in this paper with the
SOFI infrared camera attached to the ESO New Technology Telescope. It
was possible to collect deep Js and Ks images of six distinct SMC
fields during three nights in 2007, and of three more fields over two
nights in 2008.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 83 13 Observational information on the target fields
table3.dat 95 59 Individual Js- and Ks-band observations of
RR Lyrae stars in SMC fields
table4.dat 70 34 Averaged and extinction-corrected magnitudes of
observed RR Lyrae stars
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See also:
J/AcA/60/165 : VI light curves of SMC RR Lyrae (Soszynski+, 2010)
J/AJ/135/1993 : JHK magnitudes of Sculptor RR Lyrae (Pietrzynski+, 2008)
J/MNRAS/353/705 : OGLE Variables in Magellanic Clouds (Ita+, 2004)
J/AcA/49/437 : BVI photometry of OGLE SMC Cepheids (Udalski+, 1999)
J/AcA/48/113 : OGLE RR Lyrae VI photometry (Udalski, 1998)
J/AcA/48/147 : OGLE SMC BVI photometry (Udalski+ 1998)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1 I1 --- Seq [1,9] Field number
3- 11 A9 --- Field Field name
13- 14 I2 h RAh Hour of right ascension (J2000)
16- 17 I2 min RAm Minute of right ascension (J2000)
19- 23 F5.2 s RAs Second of right ascension (J2000)
25 A1 --- DE- Sign of declination (J2000)
26- 27 I2 deg DEd Degree of declination (J2000)
29- 30 I2 arcmin DEm Arcminute of declination (J2000)
32- 36 F5.2 arcsec DEs Arcsecond of declination (J2000)
38- 47 A10 "YYYY/MM/DD" Date UT date of observation
49- 60 F12.6 d MJD.J Modified Julian Date of Js exposure
62- 73 F12.6 d MJD.K Modified Julian Date of Ks exposure
75- 77 A3 --- Cond Conditions (CLR or STD)
79- 83 F5.3 mag E(B-V) ? Extinction E(B-V) from the reddening maps
of Udalski et al. 1999 (Cat. J/AcA/49/437)
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 10 A10 "YYYY/MM/DD" Date Observation date
12- 15 A4 --- --- [OGLE]
16- 33 A18 --- OGLE Star identification (HHMMSS.ss+DDMMSS.s; J2000)
35- 36 A2 --- Type [ab/c ] RR Lyrae type
38- 45 F8.6 d Per Period
47- 55 A9 --- Field Field name
57- 62 F6.3 mag Jsmag ? ESO/SOFI calibrated Js-band magnitude
64- 68 F5.3 mag e_Jsmag ? Jsmag uncertainty
70- 75 F6.3 mag Ksmag ? ESO/SOFI calibrated Ks-band magnitude
77- 81 F5.3 mag e_Ksmag ? Ksmag uncertainty
83- 95 A13 --- Comm Remarks (Blend, Contaminated or Misidentified)
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 4 A4 --- --- [OGLE]
5- 22 A18 --- OGLE Star identification (HHMMSS.ss+DDMMSS.s; J2000)
24- 25 A2 --- Type [ab/c ] RR Lyrae type
27- 34 F8.6 d Per Period
36- 44 A9 --- Field Field name
46- 51 F6.3 mag Jmag0 Mean corrected Js-band magnitude (1)
53- 57 F5.3 mag e_Jmag0 Jsmag uncertainty
59- 64 F6.3 mag Kmag0 Mean corrected Ks-band magnitude (1)
66- 70 F5.3 mag e_Kmag0 Ksmag uncertainty
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Note (1): We have corrected the observed magnitudes for extinction,
adopting the reddening values published by Udalski et al. (1999, Cat.
J/AcA/49/437) which are shown in Table 1. Adopting the reddening law
from Schlegel et al. (1998ApJ...500..525S 1998ApJ...500..525S), we calculate the following
selective extinctions in the different bands: AK=0.367E(B-V) and
AJ=0.902E(B-V). See section 3 for further details.
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History:
From electronic version of the journal
(End) Emmanuelle Perret [CDS] 24-Jan-2012