J/ApJ/912/165 Massive white dwarfs in young star clusters (Richer+, 2021)
Massive white dwarfs in young star clusters.
Richer H.B., Caiazzo I., Du H., Grondin S., Hegarty J., Heyl J., Kerr R.,
Miller D.R., Thiele S.
<Astrophys. J., 912, 165 (2021)>
=2021ApJ...912..165R 2021ApJ...912..165R
ADC_Keywords: Clusters, open; Stars, white dwarf; Magnitudes, absolute; Colors;
Photometry; Optical; Stars, masses; Stars, ages; Proper motions
Keywords: White dwarf stars ; Chandrasekhar limit ; Supernovae ;
Compact objects ; Open star clusters ; Young star clusters
Abstract:
We have carried out a search for massive white dwarfs (WDs) in the
direction of young open star clusters using the Gaia DR2 database. The
aim of this survey was (1) to provide robust data for new and
previously known high-mass WDs regarding cluster membership, (2) to
highlight WDs previously included in the initial final mass relation
(IFMR) that are unlikely members of their respective clusters
according to Gaia astrometry, and (3) to select an unequivocal WD
sample that could then be compared with the host clusters' turnoff
masses. All promising WD candidates in each cluster color-magnitude
diagram were followed up with spectroscopy from Gemini in order to
determine whether they were indeed WDs and derive their masses,
temperatures, and ages. In order to be considered cluster members,
white dwarfs were required to (1) have proper motions and parallaxes
within 2σ, 3σ, or 4σ of those of their potential
parent cluster based on how contaminated the field was in their region
of the sky, (2) have a cooling age that was less than the cluster age,
and (3) have a mass that was broadly consistent with the IFMR. A
number of WDs included in current versions of the IFMR turned out to
be nonmembers, and a number of apparent members, based on Gaia's
astrometric data alone, were rejected, as their mass and/or cooling
times were incompatible with cluster membership. In this way, we
developed a highly selected IFMR sample for high-mass WDs that,
surprisingly, contained no precursor masses significantly in excess of
∼6M☉.
Description:
Table 1 lists all of the identified candidate white dwarfs (WDs) along
with the handful of well-studied WDs appearing in
Cummings+ (2018ApJ...866...21C 2018ApJ...866...21C).
Table 4 contains select parameters for clusters associated with wide
search WDs, as well as a number of WD parameter estimates if they are
indeed cluster members. We emphasize that this is not a list of WDs
that are necessarily cluster members; instead, it is a list of WDs
that could be part of these clusters and are worth considering in
future work.
Table 5 contains information on the young open clusters that were
searched for potential massive WDs in the narrow search. While WEBDA
provided the source list for the majority of these clusters (with the
exception of six, as discussed in Section 2), all of the astrometric
information contained in the table was derived by the authors using
the Gaia DR2 database.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 116 35 Potential cluster member white dwarfs identified
table4.dat 104 151 Wide search WD cluster member candidates
table5.dat 131 384 Clusters studied (see Section 3)
--------------------------------------------------------------------------------
See also:
B/ocl : Optically visible open clusters and Candidates (Dias+ 2002-2015)
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
J/ApJS/156/47 : DA white dwarfs from the Palomar Green Survey (Liebert+, 2005)
J/ApJ/743/138 : Spectroscopic survey of bright white dwarfs (Gianninas+, 2011)
J/AJ/145/134 : Radial velocities of 108 stars in Ruprecht 147 (Curtis+, 2013)
J/A+A/618/A93 : Gaia DR2 open clusters in the Milky Way (Cantat-Gaudin+, 2018)
J/A+A/619/A180 : Gaia DR2 phot. sensitivity curves (Maiz Apellaniz+, 2018)
J/A+A/625/A87 : Ultra-massive white dwarfs evolution models (Camisassa+, 2019)
J/MNRAS/482/4570 : Gaia DR2 white dwarf candidates (Gentile Fusillo+, 2019)
J/ApJ/901/93 : Model atm. analysis of hot WDs from SDSS DR12 (Bedard+, 2020)
J/A+A/640/A1 : Portrait Galactic disc (Cantat-Gaudin+, 2020)
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 13 A13 --- Cl Cluster name
15- 19 F5.3 --- E(Bp-Rp) [0.04/0.4] Bp-Rp color excess
21- 25 F5.3 --- e_E(Bp-Rp) [0.004/0.03] E(Bp-Rp) uncertainty
27- 45 I19 --- Gaia Gaia DR2 identifier
47 A1 --- f_Gaia Flag on Gaia (1)
49- 54 F6.3 mag Gmag [16.6/20.93] Gaia DR2 observed G-band magnitude
56- 60 F5.3 mag e_Gmag [0.001/0.02] Uncertainty on the Gmag
62- 67 F6.3 mag Bp-Rp [-0.51/0.4] Gaia DR2 Bp-Rp color index
69- 73 F5.3 mag e_Bp-Rp [0.013/0.6] Bp-Rp uncertainty
75- 80 F6.3 mag GMag [8.9/12.1] Absolute Gaia G-band magnitude, G0
82- 86 F5.3 mag e_GMag [0.01/1.2] Gmag0 uncertainty
88- 93 F6.3 mag Bp-Rp0 [-0.65/0.3] (Bp-Rp)0 color index
95- 99 F5.3 mag e_Bp-Rp0 [0.013/0.6] Bp-Rp0 uncertainty
101-112 A12 --- Comm Comment
114 I1 --- n_Comm [1/5]? Reference or note (2)
116 A1 --- f_Comm Flag on Comm (1)
--------------------------------------------------------------------------------
Note (1): Flag as follows:
a = the object does not appear in the
Gentile Fusillo+ (2019, J/MNRAS/482/4570) catalog.
b = the object fell just outside the narrow search range, i.e.,
a 2σ cut in parallax and proper motion of the cluster, but was
nevertheless included in our sample of followed-up WDs.
c = an object that passed the 2σ cuts but had an excess factor >1.5
* = the object missed the original Gaia queries
Note (2): Code as follows:
1 = WD appeared to be below 0.6M☉ in the cluster CMD and was judged
to be a nonmember and was not pursued further
2 = Dobbie et al. (2012MNRAS.423.2815D 2012MNRAS.423.2815D)
3 = Dobbie et al. (2004MNRAS.355L..39D 2004MNRAS.355L..39D)
4 = Gianninas et al. (2011, J/ApJ/743/138)
5 = Curtis+ (2013, J/AJ/145/134) but initial mass below 2.5M☉ and
cluster too old (Marigo+ 2020NatAs...4.1102M 2020NatAs...4.1102M).
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table4.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 13 A13 --- Cl Cluster identifier
15- 19 F5.2 pc Diam [1.76/23.14] WEBDA cluster diameter
21- 24 F4.2 Msun MassTO [3.47/8] Current cluster MS turnoff mass (1)
26- 44 I19 --- Gaia Gaia DR2 source identifier
46- 50 F5.2 mag GMag [9.3/12.1] Absolute Gaia DR2 magnitude, G0 (2)
52- 56 F5.2 mag Bp-Rp0 [-0.9/-0.12] Intrinsic Gaia DR2 (Blue-Red) band
color (3)
58- 62 F5.2 --- Dist [0.7/20.3] Distance from cluster center
in units of cluster radii
64 A1 --- l_Mass Limit flag on Mass
66- 69 F4.2 Msun Mass [0.4/1.3] Estimated white dwarf mass
from cooling model fits
71 A1 --- lBMass Limit flag on B_Mass
73- 76 F4.2 Msun B_Mass [0.76/1.3] Upper 1σ uncertainty boundary
in Mass
78 A1 --- lbMass Limit flag on b_Mass
80- 83 F4.2 Msun b_Mass [0.2/1.3] Lower 1σ uncertainty boundary
in Mass
85- 90 F6.2 Myr Age [0.14/296]? Estimated white dwarf age
from model fits
92- 97 F6.2 Myr B_Age [0.17/208]? Upper 1σ uncertainty
boundary in Age
99- 104 F6.2 Myr b_Age [0.14/404]? Lower 1σ uncertainty
boundary in Age
--------------------------------------------------------------------------------
Note (1): Using IFMR from Cummings+ (2018ApJ...866...21C 2018ApJ...866...21C).
Note (2): Using associated cluster distance and reddening and
AG=2.059E(Bp-Rp), see Table 5).
Note (3): Using associated cluster reddening and
AG=2.059E(Bp-Rp), see Table 5).
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table5.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 15 A15 --- Cl Cluster identifier
17- 20 I4 --- Ns [14/2396]? Number of stars
22- 24 I3 Myr Age [4/813]? Cluster age
26- 28 I3 Myr e_Age [2/388]? 1σ uncertainty in Age
30- 31 A2 --- f_Age Flag on Age (1)
33- 39 F7.3 deg RAdeg ? Cluster center right Ascension (J2000)
41- 45 F5.3 deg e_RAdeg [0.1/3]? 1σ uncertainty in RAdeg
47- 53 F7.3 deg DEdeg [-67/72]? Cluster center declination (J2000)
55- 59 F5.3 deg e_DEdeg [0.1/2.7]? 1σ uncertainty in DEdeg
61- 67 F7.3 mas/yr pmRA [-36.2/22.7]? Cluster proper motion along RA
69- 73 F5.3 mas/yr e_pmRA [0.1/1.4]? 1σ uncertainty in pmRA
75- 81 F7.3 mas/yr pmDE [-45.5/23.5]? Cluster proper motion along DE
83- 87 F5.3 mas/yr e_pmDE [0.07/1.5]? 1σ uncertainty in pmDE
89- 93 F5.3 mas plx [0.14/7.35]? Cluster parallax
95- 99 F5.3 mas e_plx [0.07/1.7]? 1σ uncertainty in plx
101- 103 I3 --- Nred [7/776]? Number of stars used to determine
reddening
105- 109 F5.3 mag E(Bp-Rp) [0.03/1.4]? Mean cluster reddening in Gaia
filters
111- 115 F5.3 mag e_E(Bp-Rp) [0.003/0.2]? 1σ uncertainty in E(Bp-Rp)
117- 122 F6.2 --- Nwd [0/327]? Expected number of white dwarfs
produced
124- 129 F6.2 --- e_Nwd [0.05/179]? 1σ uncertainty in Nwd
131 A1 --- f_Nwd [#] # = NWD can not be determined
--------------------------------------------------------------------------------
Note (1): Flag as follows:
CG = Age from Cantat-Gaudin+ (2020, J/A+A/640/A1).
H = Manual age from this work.
NA = No age determination was possible.
--------------------------------------------------------------------------------
History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 03-Nov-2022