J/ApJ/512/48 VI photometry of new Cepheids in NGC 4725 (Gibson+, 1999)
The Hubble Space Telescope key project on the extragalactic distance scale.
XVII. The Cepheid distance to NGC 4725
Gibson B.K., Hughes S.M.G., Stetson P.B., Freedman W.L., Kennicutt R.C.Jr,
Mould J.R., Bresolin F., Ferrarese L., Ford H.C., Graham J.A., Han M.,
Harding P., Hoessel J.G., Huchra J.P., Illingworth G.D., Kelson D.D.,
Macri L.M., Madore B. F., Phelps R.L., Prosser C.F., Saha A., Sakai S.,
Sebo K.M., Silbermann N.A., Turner A.M.
<Astrophys. J. 512, 48 (1999)>
=1999ApJ...512...48G 1999ApJ...512...48G
ADC_Keywords: Stars, variable ; Photometry
Mission_Name: HST
Keywords: Cepheids - distance scale - galaxies: distances and redshifts -
galaxies: individual (NGC 4725)
Abstract:
The distance to NGC 4725 has been derived from Cepheid variables as
part of the Hubble Space Telescope Key Project on the Extragalactic
Distance Scale. Thirteen F555W (V) and four F814W (I) epochs of
cosmic-ray-split Wide Field and Planetary Camera 2 observations were
obtained. Twenty Cepheids were discovered, with periods ranging from
12 to 49 days. Adopting a Large Magellanic Cloud distance modulus and
extinction of 18.50±0.10 mag and E(V-I)=0.13 mag, respectively, a
true reddening-corrected distance modulus (based on an analysis
employing the ALLFRAME software package) of 30.50±0.16 (random)
±0.17 (systematic) mag was determined for NGC 4725. The
corresponding of distance of 12.6±1.0 (random) ±1.0
(systematic) Mpc is in excellent agreement with that found with an
independent analysis based upon the DoPHOT photometry package. With a
foreground reddening of only E(V-I)=0.02, the inferred intrinsic
reddening of this field in NGC 4725, E(V-I)=0.19, makes it one of the
most highly reddened fields encountered by the HST Key Project to
date.
Objects:
------------------------------------------
RA (2000) DE Designation(s)
------------------------------------------
12 50 27 +25 30 6 NGC 4725 = UGC 7989
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File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table4.dat 43 20 Cepheid candidates detected in NGC 4725
table5.dat 106 20 Detected Cepheid candidates's properties
table6a.dat 32 540 V band magnitudes and errors
table6b.dat 35 181 I band magnitudes and errors
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See also:
J/ApJ/463/26 : Extragalactic Distance Scale Key Project. III (Kelson+ 1996)
J/ApJ/507/655 : VI photometry of new Cepheids in NGC 2541 (Ferrarese+, 1998)
J/ApJ/508/491 : M101 Cepheids (Stetson+, 1998)
J/ApJ/521/155 : Extragalactic distance scale key project. XVIII.
(Macri+, 1999)
J/ApJ/514/614 : VI photometry of new Cepheids in NGC 3198 (Kelson+, 1999)
J/ApJ/529/723 : VI photometry of Cepheids (Gibson+, 2000)
Byte-by-byte Description of file: table4.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 A3 --- Ceph Cepheid identification number
8 I1 --- Chip WFPC chip cepheid is located on (1 is the
PC chip)
10- 14 F5.1 --- XPix The x pixel coordinate
16- 20 F5.1 --- YPix The y pixel coordinate
22- 23 I2 h RAh Right Ascension (J2000)
25- 26 I2 min RAm Right Ascension (J2000)
28- 32 F5.2 s RAs Right Ascension (J2000)
34- 35 I2 deg DEd Declination (J2000)
37- 38 I2 arcmin DEm Declination (J2000)
40- 43 F4.1 arcsec DEs Declination (J2000)
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table5.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 A3 --- Ceph Cepheid identification number
6- 10 F5.2 d Per Cepheid period from ALLFRAME
13- 16 F4.2 d e_Per Uncertainty in Per
18- 22 F5.2 mag Vmag V band magnitude from ALLFRAME
25- 28 F4.2 mag e_Vmag Uncertainty in Vmag
30- 34 F5.2 mag Imag I band magnitude from ALLFRAME
37- 40 F4.2 mag e_Imag Uncertainty in Imag
42- 45 F4.1 d DPer Cepheid period from DoPHOT
47- 51 F5.2 mag DVmag V band magnitude from DoPHOT
54- 57 F4.2 mag e_DVmag Uncertainty in DVmag
59- 63 F5.2 mag DImag I band magnitude from DoPHOT
66- 69 F4.2 mag e_DImag Uncertainty in Imag
72-111 A40 --- Com Comments on Cepheids canidates
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Byte-by-byte Description of file: table6a.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 A3 --- Ceph Cepheid identification number
6- 14 F9.3 d JD Julian date of observation (JD-2440000.000)
18 A1 --- Filt Filter used in observation
21- 25 F5.2 mag Vmag Observed magnitude in the Filt band
28- 31 F4.2 mag e_Vmag Uncertainty in Vmag
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table6b.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 A3 --- Ceph Cepheid identification number
6- 14 F9.3 d JD Julian date of observation (JD-2440000.000)
18 A1 --- Filt Filter used in observation
21- 25 F5.2 mag Imag ? Observed magnitude in the Filt band
28- 31 F4.2 mag e_Imag ? Uncertainty in Imag
--------------------------------------------------------------------------------
History:
From ApJ electronic edition.
References:
(Paper I) Freedman+ 1994ApJ...427..628F 1994ApJ...427..628F
(Paper II) Hughes+ 1994ApJ...428..143H 1994ApJ...428..143H
(Paper III) Kelson+ 1996ApJ...463...26K 1996ApJ...463...26K, Cat. J/ApJ/463/26
(Paper IV) Ferrarese+ 1996ApJ...464..568F 1996ApJ...464..568F
(Paper VI) Silbermann+ 1996ApJ...470....1S 1996ApJ...470....1S
(Paper VII) Graham+ 1997ApJ...477..535G 1997ApJ...477..535G
(Paper VIII) Rawson+ 1997ApJ...490..517R 1997ApJ...490..517R
(Paper IX) Phelps+ 1998ApJ...500..763P 1998ApJ...500..763P
(Paper X) Hughes+ 1998ApJ...501...32H 1998ApJ...501...32H
(Paper XI) Turner+ 1998ApJ...505..207T 1998ApJ...505..207T
(Paper XII) Ferrarese+ 1998ApJ...507..655F 1998ApJ...507..655F, Cat. J/ApJ/507/655
(Paper XIII) Kennicutt+ 1998ApJ...498..181K 1998ApJ...498..181K
(Paper XIV) Silbermann+ 1999ApJ...515....1S 1999ApJ...515....1S
(Paper XV) Madore+ 1999ApJ...515...29M 1999ApJ...515...29M
(Paper XVI) Stetson+ 1998ApJ...508..491S 1998ApJ...508..491S
(Paper XVIII) Macri+ 1999ApJ...521..155M 1999ApJ...521..155M, Cat. J/ApJ/521/155
(Paper XIX) Kelson+ 1999ApJ...514..614K 1999ApJ...514..614K
(Paper XX) Graham+ 1999ApJ...516..626G 1999ApJ...516..626G
(Paper XXI) Mould+ 2000ApJ...528..655M 2000ApJ...528..655M
(Paper XXII) Prosser+ 1999ApJ...525...80P 1999ApJ...525...80P
(Paper XXIII) Sakai+ 1999ApJ...523..540S 1999ApJ...523..540S
(Paper XXIV) Sakai+ 2000ApJ...529..698S 2000ApJ...529..698S
(Paper XXV) Gibson+ 2000ApJ...529..723G 2000ApJ...529..723G, Cat. J/ApJ/529/723
(Paper XXVI) Ferrarese+ 2000ApJ...529..745F 2000ApJ...529..745F
(Paper XXVII) Kelson+ 2000ApJ...529..768K 2000ApJ...529..768K
(Paper XXVIII) Mould+ 2000ApJ...529..786M 2000ApJ...529..786M
(End) Greg Schwarz [AAS] 29-Feb-2000