J/A+A/678/A44 Messier 51 Cepheid catalogue (Csoernyei+, 2023)
Reeling in the Whirlpool galaxy:
Distance to M 51 clarified through Cepheids and the Type IIP SN 2005cs.
Csoernyei G., Anderson R.I., Vogl C., Taubenberger S., Blondin S.,
Leibundgut B., Hillebrandt W.
<Astron. Astrophys. 678, A44 (2023)>
=2023A&A...678A..44C 2023A&A...678A..44C (SIMBAD/NED BibCode)
ADC_Keywords: Stars, variable ; Positional data ; Photometry, HST ; Optical ;
Galaxies, nearby
Keywords: stars: distances - stars: variables: Cepheids -
supernovae: individual: SN 2005cs - radiative transfer
Abstract:
The distance to the Whirlpool galaxy, M 51, is still debated, even
though the galaxy has been studied in great detail. Current estimates
range from 6.02 to 9.09Mpc, and different methods yield discrepant
results. No Cepheid distance has been published for M 51 to date.
We aim to estimate a more reliable distance to M 51 through two
independent methods: Cepheid variables and their period-luminosity
relation, and an augmented version of the expanding photosphere method
(EPM) on the type IIP supernova SN 2005cs, which exploded in this
galaxy.
For the Cepheid variables, we analysed a recently published Hubble
Space Telescope catalogue of stars in M 51. By applying filtering
based on the light curve and colour-magnitude diagram, we selected a
high-quality sample of M 51 Cepheids to estimate the distance through
the period-luminosity relation. For SN 2005cs, an emulator-based
spectral fitting technique was applied, which allows for the fast and
reliable estimation of the physical parameters of the supernova
atmosphere. We augmented the established framework of EPM with these
spectral models to obtain a precise distance to M 51.
The two resulting distance estimates are DCep=7.59±0.30Mpc and
D2005cs=7.34±0.39Mpc using the Cepheid period-luminosity relation
and the spectral modelling of SN 2005cs, respectively. This is the
first published Cepheid distance for this galaxy. The obtained values
are precise to 4-5% and are fully consistent within 1σ
uncertainties. Because these two estimates are completely independent,
they can be combined for an even more precise estimate, which yields
DM51=7.50±0.24Mpc (3.2% uncertainty).
Our distance estimates agree with most of the results obtained
previously for M 51, but they are more precise than the earlier
counterparts. However, they are significantly lower than the TRGB
estimates, which are often adopted for the distance to this galaxy.
The results highlight the importance of direct cross-checks between
independent distance estimates so that systematic uncertainties can be
quantified. Because of the large discrepancy, this finding can also
affect distance-sensitive studies and their discussion for objects
within M 51, as well as the estimation of the Hubble constant through
the type IIP standardizable candle method, for which SN 2005cs is a
calibrator object.
Description:
Cepheid variable stars provide the most precise and reliable way to
date to infer distances to galaxies outside the Local Group. Deriving
the period-luminosity relation however requires extensive set of
observations, hence the number of host galaxies with known Cepheid
distance is still limited. Here, we present a catalogue of Cepheid
variable stars in the nearby galaxy Messier 51 (NGC 5194). This
catalogue was derived from the massive stellar variability census of
Conroy et al. (2018ApJ...864..111C 2018ApJ...864..111C, Cat. J/ApJ/864/111), which
collected data for Messier 51 using the Hubble Space Telescope
throughout Cycle 24. We applied multiple automatic filterings on this
dataset, which allowed us to select the Cepheid variables reliably: a
filter based on the periodicity of the stars, their light curve shape,
and then finally, a filter based on their position on the
colour-magnitude diagram. These three filters then yielded us a set of
638 Cepheid variables, which were then used to infer the distance
Messier 51. This data alone allowed for a 3% precise distance
estimate, which is competitive current day's cutting edge
uncertainties.
The main data presented in this paper is a subset of the catalogue
published by Conroy et al. (2018ApJ...864..111C 2018ApJ...864..111C, Cat. J/ApJ/864/111).
We present the data necessary to perform the Cepheid based distance
estimation for Messier 51 using the stars selected by our filtering
techniques, such as period, brightness (F555W, F606W and F814W), and
Wesenheit magnitude values. We include metallicity measurements for
each sample stars as well, which were derived based on the metallicity
gradient estimated by Zaritsky et al. (1994ApJ...420...87Z 1994ApJ...420...87Z).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
ceps.dat 117 638 Catalogue of M 51 Cepheid variables
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See also:
J/ApJ/715/277 : Insights into the Cepheid distance scale (Bono+, 2010)
J/ApJ/730/119 : HST/WFC3 obs. of Cepheids in SN Ia hosts (Riess+, 2011)
J/ApJ/733/124 : Cepheids in M101 observed with HST (Shappee+, 2011)
J/AJ/144/113 : Cepheids and companions in M33 from HST images (Chavez+, 2012)
J/ApJ/748/107 : A global model for MC and Galactic Cepheids (Pejcha+, 2012)
J/ApJ/777/79 : HST photometry of Cepheid candidates in M101 (Mager+, 2013)
J/AJ/145/106 : M31 Cepheid disk sample of 1st year of PS1 (Kodric+, 2013)
J/AJ/149/183 : gri photometry of variables in NGC 4258 (Hoffmann+, 2015)
J/AJ/149/117 : LMC infrared survey. I. Photometry of Cepheids (Macri+, 2015)
J/ApJ/799/144 : M31 Cepheids in near-IR (Kodric+, 2015)
J/ApJ/830/10 : >20yrs of HST obs. of Cepheids in SNIa host gal.
(Hoffmann+, 2016)
J/ApJ/826/56 : HST/WFC3 obs. of Cepheids in SN Ia host gal. (Riess+, 2016)
J/A+A/587/A70 : CALIFA face-on spiral gal. oxygen (Sanchez-Menguiano+, 2016)
J/AJ/156/30 : Cepheids in M31 - PAndromeda Cepheid sample (Kodric+, 2018)
J/ApJ/864/111 : HST/ACS one-year observations of M51 stars (Conroy+, 2018)
Byte-by-byte Description of file: ceps.dat
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Bytes Format Units Label Explanations
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1- 10 F10.6 deg RAdeg Right Ascension (J2000)
12- 20 F9.6 deg DEdeg Declination (J2000)
22- 30 F9.6 d P Fourier period at maximum power in F814W
32- 40 F9.6 mag F555W HST/F555W band (V) flux averaged brightness
42- 49 F8.6 mag e_F555W Uncertainty in F555Wmag
51- 59 F9.6 mag F606W HST/F606W band (V) flux averaged brightness
61- 68 F8.6 mag e_F606W Uncertainty in F606Wmag
70- 78 F9.6 mag F814W HST/F814W band (I) flux averaged brightness
80- 87 F8.6 mag e_F814W Uncertainty in F814Wmag
89- 97 F9.6 mag WVI-555 Wesenheit magnitude inferred based on
F555W and F814W
99-106 F8.6 mag e_WVI-555 Uncertainty in the Wesenheit magnitude
108-115 F8.6 [-] Z Zaritsky et al. (1994ApJ...420...87Z 1994ApJ...420...87Z)
metallicity values
117 A1 --- sig-clip [+] Boolean value for the Cepheid being
included in the final PL relation fit.
If '+', it was included, otherwise was
discarded by the sigma clipping
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Acknowledgements:
Geza Csoernyei, csogeza(at)mpa-garching.mpg.de
(End) Patricia Vannier [CDS] 01-Aug-2023