J/ApJ/898/L7 Predicted masses of Gal. Cepheids from Gaia (Marconi+, 2020)
Predicted masses of Galactic Cepheids in the Gaia Data Release 2.
Marconi M., De Somma G., Ripepi V., Molinaro R., Musella I., Leccia S.,
Moretti M.I.
<Astrophys. J., 898, L7 (2020)>
=2020ApJ...898L...7M 2020ApJ...898L...7M
ADC_Keywords: Stars, variable; Stars, masses; Parallaxes, trigonometric;
Photometry; Optical
Keywords: Cepheid variable stars ; Cepheid distance ; Distance indicators ;
Stellar pulsations ; Stellar oscillations ; Stellar evolution
Abstract:
On the basis of recently computed nonlinear convective pulsation
models of Galactic Cepheids, spanning wide ranges of input stellar
parameters, we derive theoretical mass-dependent Period-Wesenheit
relations in the Gaia bands, namely, G, GBP, and GBR, that are
found to be almost independent of the assumed efficiency of
superadiabatic convection. The application to a selected subsample of
the Gaia Data Release 2 Galactic Cepheids database allows us to derive
mass-dependent estimates of their individual distances. By imposing
their match with the astrometric values inferred from Gaia, we are
able to evaluate the individual mass of each pulsator. The inferred
mass distribution is peaked around 5.6M☉ and 5.4M☉ for the
F and FO pulsators, respectively. If the estimated Gaia parallax
offset <Δω≥0.046mas is applied to Gaia parallaxes before
imposing their coincidence with the theoretical ones, the inferred
mass distribution is found to shift toward lower masses, namely,
∼5.2M☉ and 5.1M☉ for the F and FO pulsators, respectively.
The comparison with independent evaluations of the stellar masses, for
a subset of binary Cepheids in our sample, seems to support the
predictive capability of the current theoretical scenario. By forcing
the coincidence of our mass determinations with these literature
values we derive an independent estimate of the mean offset to be
applied to Gaia DR2 parallaxes, <Δω≥0.053±0.029mas,
slightly higher but in agreement within the errors with the
Riess+ 2018ApJ...861..126R 2018ApJ...861..126R value.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 79 145 The individual masses estimated from the theoretical
period-Wesenheit (PWM) relations combined with
Gaia DR2 parallaxes, for the fundamental (F) and
first overtone (FO)-mode Galactic Classical Cepheid
in the selected sample
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See also:
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
J/AJ/142/87 : Velocities and light curves of V350 Sgr (Evans+, 2011)
J/ApJ/730/119 : HST/WFC3 obs. of Cepheids in SN Ia hosts (Riess+, 2011)
J/ApJ/813/29 : Classical and type II Cepheids IR excesses (Schmidt, 2015)
J/A+A/622/A60 : Gaia DR2 misclassified RR Lyrae list (Clementini+, 2019)
J/A+A/623/A117 : Gal. Cepheids & RR Lyrae multiplicity. II (Kervella+, 2019)
J/ApJ/876/85 : HST observations for LMC Cepheids (Riess+, 2019)
J/A+A/625/A14 : Reclassification of Cepheids in the Gaia DR2 (Ripepi+, 2019)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 19 I19 --- Gaia Gaia DR2 source identifier
21- 22 A2 --- Mode Pulsation mode ("F" (114 occurrences) or "FO")
24- 31 F8.5 d Per [1.1/41.5] Pulsation period
33- 37 F5.2 mag Gmag [4.2/12.3] Apparent Gaia G band magnitude
39- 43 F5.2 mag BPmag [4.7/13.4] Apparent Gaia Blue passband magnitude
45- 49 F5.2 mag RPmag [3.7/11.3] Apparent Gaia Red passband magnitude
51- 55 F5.3 mas plx [0.25/3.44] Parallax
57- 61 F5.3 mas e_plx [0.02/0.21] Uncertainty in plx
63- 66 F4.1 Msun Mass [2.3/12.8] Mass
68- 70 F3.1 Msun e_Mass [0.3/2.0] Uncertainty in Mass
72- 75 F4.1 Msun Mc [1.7/11.8] Corrected mass
77- 79 F3.1 Msun e_Mc [0.3/1.6] Uncertainty in Mc
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDs] 08-Dec-2021