J/ApJ/699/539 Cepheids in SN-Ia host galaxies (Riess+, 2009)
A redetermination of the Hubble constant with the Hubble space telescope from a
differential distance ladder.
Riess A.G., Macri L., Casertano S., Sosey M., Lampeitl H., Ferguson H.C.,
Filippenko A.V., Jha S.W., Li W., Chornock R., Sarkar D.
<Astrophys. J., 699, 539-563 (2009)>
=2009ApJ...699..539R 2009ApJ...699..539R
ADC_Keywords: Stars, variable ; Photometry, HST ; Supernovae
Keywords: cosmology: observations - distance scale - galaxies: distances and
redshifts - supernovae: general
Abstract:
This is the second of two papers reporting results from a program to
determine the Hubble constant to ∼5% precision from a refurbished
distance ladder based on extensive use of differential measurements.
Here we report observations of 240 Cepheid variables obtained with the
Near-Infrared Camera and Multi-Object Spectrometer (NICMOS) Camera 2
through the F160W filter on the Hubble Space Telescope (HST). The
Cepheids are distributed across six recent hosts of Type Ia supernovae
(SNe Ia) and the "maser galaxy" NGC 4258, allowing us to directly
calibrate the peak luminosities of the SNe Ia from the precise,
geometric distance measurements provided by the masers. New features
of our measurement include the use of the same instrument for all
Cepheid measurements across the distance ladder and homogeneity of the
Cepheid periods and metallicities, thus necessitating only a
differential measurement of Cepheid fluxes and reducing the largest
systematic uncertainties in the determination of the fiducial SN Ia
luminosity. In addition, the NICMOS measurements reduce the effects of
differential extinction in the host galaxies by a factor of ∼5 over
past optical data. Combined with a greatly expanded set of 240 SNe Ia
at z<0.1 which define their magnitude-redshift relation, we find
H0=74.2±3.6km/s/Mpc, a 4.8% uncertainty including both statistical
and systematic errors.
Description:
The goal of the Supernovae and H0 for the Equation of State (SHOES)
Program (HST Cycle 15, GO-10802) is to measure H0 to <5% precision
by mitigating the dominant systematic errors. Here we reporting the
results of infrared (IR) observations of Cepheids which are homogeneous
in their periods, metallicities, and measurements in both the anchor
(NGC 4258) and the SN hosts.
In HST Cycle 15, the SHOES program obtained deep (10-35ks), near-IR
observations of the Cepheids in six SN Ia hosts. In Cycle 15, we also
obtained 2 ks NICMOS imaging of Cepheids in NGC 4258 to augment that
obtained in Cycle 13 by GO 10399 (P.I. Greenhill).
File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table3.dat 67 61 NIC2 F160W Cepheid observations
table4.dat 97 240 NICMOS Cepheids
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See also:
J/ApJS/183/109 : Cepheids in 3 host galaxies (Riess+, 2009)
J/ApJ/652/1133 : BVI photometry of NGC 4258 Cepheids (Macri+, 2006)
J/ApJ/627/579 : Photometry of variables in NGC 3370 (Riess+, 2005)
J/ApJ/529/723 : VI photometry of Cepheids (Gibson+, 2000)
Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 20 A20 --- Target Target designation (1)
21 A1 --- n_Target [a] Duplicated field (2)
23- 24 I2 h RAh Hour of right ascension (J2000)
26- 27 I2 min RAm Minute of right ascension (J2000)
29- 34 F6.3 s RAs Second of right ascension (J2000)
36 A1 --- DE- Sign of declination (J2000)
37- 38 I2 deg DEd Degree of declination (J2000)
40- 41 I2 arcmin DEm Arcminute of declination (J2000)
43- 48 F6.3 arcsec DEs Arcsecond of declination (J2000)
50- 56 F7.1 s ExpT Exposure time
58- 67 A10 --- Field Field designation as in table 4 (added by CDS)
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Note (1): Cepheid hosts observed by SHOES (Supernovae and H0 for the
Equation of State program) in optical (see Paper I, Riess et al. 2009,
Cat. J/ApJS/183/109) and NIR:
------------------------------------------------------------------------
Host SN Ia Initial HST Reobservation, NIR, Cycle 15
Optical Cycle Cycle 15 (and 13 for NGC 4258)
------------------------------------------------------------------------
NGC 4536 SN 1981B WFPC2 4 WFPC2 NIC2
NGC 4639 SN 1990N WFPC2 5 ACS NIC2
NGC 3982 SN 1998aq WFPC2 8 ACS NIC2
NGC 3370 SN 1994ae ACS 11 ACS NIC2
NGC 3021 SN 1995al ACS 14 ACS NIC2
NGC 1309 SN 2002fk ACS 14 ACS NIC2
NGC 4258 ACS 12 ACS/WFPC2 NIC2
------------------------------------------------------------------------
Note (2):
a = Same region as NGC4639-BLUE with different orientation.
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Byte-by-byte Description of file: table4.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 10 A10 --- Field Cepheid's NIC2 field designation
12- 21 F10.6 deg RAdeg Right ascension in decimal degrees (J2000)
23- 32 F10.6 deg DEdeg Declination in decimal degrees (J2000)
34- 39 I6 --- [RML2009] Identification number (1)
41- 47 F7.3 d Per Period
49- 52 F4.2 mag V-I Mean (V-I) color index
54- 58 F5.2 mag F160W HST/NICMOS NIR F160W band magnitude
60- 63 F4.2 mag e_F160W F160W uncertainty
65- 69 F5.2 pix Offset Separation between NICMOS and optical
position (2)
71- 75 F5.2 mag Bias Photometric bias (3)
77- 81 F5.2 mag Phase Correction from the sampled phase to the mean
(already substracted to determine F160W)
83- 86 F4.2 [---] [O/H] Metallicity parameter, 12+log[O/H] inferred at
the position of each Cepheid
88- 93 A6 --- Flag [<P/rej, ] Rejection flag employed (4)
95- 97 A3 --- r_V-I [lm/psl] Source of the optical detection (5)
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Note (1): From
* Riess et al. 2009, Cat. J/ApJS/183/109, <[RML2009] NGC NNNN NNNNN>
in Simbad)
* Macri et al. 2006, Cat. J/ApJ/652/1133, <[MSB2006] {O/I}-NNNNNN>
in Simbad.
* Cepheids from this paper are <[RMC2009] {Field} NNNNN> in Simbad.
Note (2): Displacement of the Cepheid in the NICMOS data from its optical
position in pixels of 0.038" size.
Note (3): Photometric bias determined from the artificial star tests for
the Cepheid's environment and displacement and are already added to
determine F160W magnitude.
Note (4): Flag as follows:
<P = the period is shorter than the optical completeness from Riess et al.
2009, Cat. J/ApJS/183/109.
rej = σ clipped.
Note (5): Source of optical Cepheid parameters as follows:
lm = Riess et al. 2009, Cat. J/ApJS/183/109 and Macri et al. 2009, ApJ
in prep
psl = Stetson & Gibson 2001MNRAS.328L...1S 2001MNRAS.328L...1S
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History:
From electronic version of the journal
References:
Riess et al. Paper I. 2009ApJS..183..109R 2009ApJS..183..109R Cat. J/ApJS/183/109
Riess et al. 2011ApJ...730..119R 2011ApJ...730..119R
(End) Emmanuelle Perret [CDS] 24-Jun-2011