J/ApJ/842/42 Improved reddenings for 59 Galactic Cepheids (Madore+, 2017)
A method for improving Galactic Cepheid reddenings and distances.
Madore B.F., Freedman W.L., Moak S.
<Astrophys. J., 842, 42 (2017)>
=2017ApJ...842...42M 2017ApJ...842...42M
ADC_Keywords: Stars, variable ; Reddening ; Stars, distances ;
Magnitudes, absolute ; Parallaxes, trigonometric
Keywords: Stars: variables: Cepheids
Abstract:
We present a new photometric method by which improved high-precision
reddenings and true distance moduli can be determined to individual
Galactic Cepheids once distance measurements are available. We
illustrate that the relative positioning of stars in the Cepheid
period-luminosity (PL) relation (Leavitt law) is preserved as a
function of wavelength. This information then provides a powerful
constraint for determining reddenings to individual Cepheids, as well
as their distances. As a first step, we apply this method to the 59
Cepheids in the compilation of Fouque et al. Updated reddenings,
distance moduli (or parallaxes), and absolute magnitudes in seven
(optical through near-infrared) bands are given. From these intrinsic
quantities, multiwavelength PL and color-color relations are derived.
We find that the V-band period-luminosity-color relation has an rms
scatter of only 0.06mag, so that individual Cepheid distances can be
measured to 3%, compared with dispersions of 6 to 13% for the
one-parameter K through B PL relations, respectively. This method will
be especially useful in conjunction with the new accurate parallax
sample upcoming from Gaia.
Description:
We have used a published compilation of absolute magnitudes measured
in seven bands, based on distances and reddenings independently
determined for 59 Galactic Cepheids (Fouque+ 2007, J/A+A/476/73), with
overtone and suspected overtone pulsators omitted. Where available,
HST parallaxes have been adopted for these stars, followed by Infrared
Surface Brightness (IRSB) determinations and then Interferometric
Baade-Wesselink applications and, finally, revised Hipparcos parallaxes.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 149 59 Properties of 59 Galactic Cepheids
--------------------------------------------------------------------------------
See also:
J/A+A/476/73 : Calibration of Cepheid P/L relation (Fouque+, 2007)
J/A+A/534/A95 : LMC Cepheids radial velocities (Storm+, 2011)
J/A+A/550/A70 : Galactic and MC Cepheids distance (Groenewegen, 2013)
J/AJ/149/117 : LMC infrared survey. I. Photometry of Cepheids (Macri+, 2015)
J/ApJ/826/56 : HST/WFC3 obs. of Cepheids in SN Ia host gal. (Riess+, 2016)
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 9 A9 --- Name Galactic Cepheid name
11- 18 F8.6 [d] log(P)-F07 [0.5/1.7] log Period (1)
20- 24 F5.3 mag E(B-V)-F07 [0.01/1] E(B-V) reddening (1)
26- 31 F6.3 mag DM-o-F07 [6.9/13.4] Adopted distance modulus
33- 36 F4.2 mas plx-F07 [0.2/4.2] Adopted parallax (1)
38- 41 F4.2 mas e_plx-F07 [0.01/0.3] Uncertainty in plx-F07 (1)
43- 47 F5.2 mag BMag-F07 [-5/-1.8] B band absolute magnitude (1)
49- 53 F5.2 mag VMag-F07 [-6/-2.4] V band absolute magnitude (1)
55- 59 F5.2 mag RMag-F07 [-6.6/-2.8] R band absolute magnitude (1)
61- 65 F5.2 mag IMag-F07 [-7/-3.1] I band absolute magnitude (1)
67- 71 F5.2 mag JMag-F07 [-7.6/-3.6] J band absolute magnitude (1)
73- 77 F5.2 mag HMag-F07 [-8/-3.9] H band absolute magnitude (1)
79- 83 F5.2 mag KMag-F07 [-8/-4] K band absolute magnitude (1)
85- 89 F5.3 mag E(B-V) [0.04/1.1] E(B-V) reddening, this work
91- 96 F6.3 mag DM-o [6.6/13.4] Adopted distance modulus, this work
98-102 F5.3 mas plx [0.2/4.8] Adopted parallax, this work
104-107 F4.2 mas e_plx [0.01/8] Uncertainty in parallax, this work
109-113 F5.2 mag BMag [-5/-1.6] B band absolute magnitude,
updated in this work
115-119 F5.2 mag VMag [-6/-2.3] V band absolute magnitude,
updated in this work
121-125 F5.2 mag RMag [-6.4/-2.7] R band absolute magnitude,
updated in this work
127-131 F5.2 mag IMag [-6.7/-3.1] I band absolute magnitude,
updated in this work
133-137 F5.2 mag JMag [-7.3/-3.7] J band absolute magnitude,
updated in this work
139-143 F5.2 mag HMag [-7.7/-3.9] H band absolute magnitude,
updated in this work
145-149 F5.2 mag KMag [-7.8/-4.1] K band absolute magnitude,
updated in this work
--------------------------------------------------------------------------------
Note (1): From Fouque+ 2007, J/A+A/476/73
--------------------------------------------------------------------------------
History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 26-Jan-2018