J/MNRAS/494/1448 Wide astrometric companions with Gaia DR2 (Igoshev+, 2020)
Inferred time-scales for common envelope ejection using wide astrometric
companions.
Igoshev A.P., Perets H.B., Michaely E.
<Mon. Not. R. Astron. Soc., 494, 1448-1462 (2020)>
=2020MNRAS.494.1448I 2020MNRAS.494.1448I (SIMBAD/NED BibCode)
ADC_Keywords: Stars, double and multiple ; Binaries, cataclysmic ;
Stars, white dwarf ; Stars, subdwarf ; Stars, variable ;
Binaries, orbits ; Optical
Keywords: binaries: general - stars: low-mass - stars: mass-loss -
stars: statistics
Abstract:
Evolution of close binaries often proceeds through the common envelope
stage. The physics of the envelope ejection (CEE) is not yet
understood, and several mechanisms were suggested to be involved.
These could give rise to different time-scales for the CEE mass-loss.
In order to probe the CEE-time-scales we study wide companions to
post-CE binaries. Faster mass-loss time-scales give rise to higher
disruption rates of wide binaries and result in larger average
separations. We make use of data from Gaia DR2 to search for ultrawide
companions (projected separations 103-2x105au and
M2>0.4M☉) to several types of post-CEE systems, including
sdBs, white dwarf post-common binaries, and cataclysmic variables. We
find a (wide-orbit) multiplicity fraction of 1.4±0.2 per cent for
sdBs to be compared with a multiplicity fraction of 5.0±0.2 per cent
for late-B/A/F stars which are possible sdB progenitors. The
distribution of projected separations of ultrawide pairs to main
sequence stars and sdBs differs significantly and is compatible with
prompt mass-loss (upper limit on common envelope ejection time-scales
of 102yr). The smaller statistics of ultrawide companions to
cataclysmic variables and post-CEE binaries provide weaker
constraints. Nevertheless, the survival rate of ultrawide pairs to the
cataclysmic variables suggest much longer, ∼104yr time-scales for
the CEE in these systems, possibly suggesting non-dynamical CEE in
this regime.
Description:
We use the catalogue of Main sequence - white dwarf (MSWD) binaries
compiled by Rebassa-Mansergas et al. (2007MNRAS.382.1377R 2007MNRAS.382.1377R, Cat.
J/MNRAS/382/1377) (https://www.sdss-wdms.org). This catalogue includes
3287 MSWD binaries identified in the Sloan Digital Sky Survey (York et
al. 2000AJ....120.1579Y 2000AJ....120.1579Y). Only ∼25 per cent of MSWD binaries are
classified as post-CE systems. In order to get the parallaxes and
proper motions for these stars we match these data with the second
Gaia data release (Gaia Collaboration 2018A&A...616A...1G 2018A&A...616A...1G, Cat.
I/345).
For the subdwarf systems we used the catalogue of sdBs by Geier et al.
(2019A&A...621A..38G 2019A&A...621A..38G, Cat. J/A+A/621/A38). This catalogue contains
39800 candidates selected in Gaia DR2 and includes some possible
contamination at the level of 10 per cent.
As a source for positions of cataclysmic variables we used the
catalogue of Ritter & Kolb (2003A&A...404..301R 2003A&A...404..301R, Cat. B/cb) which
contains 1429 objects. Because CVs are very variable in the optical
band, we used only the coordinate information in our identification
and did not perform magnitude or colour analysis.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table2.dat 104 21 Resolved binaries found in the MSWD sample
table3.dat 104 42 Wide binaries found in the MSWD sample
table4.dat 108 64 The identified sdB systems with wide companions
table5.dat 92 14 Wide binaries found in the CVs sample
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See also:
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
J/MNRAS/382/1377 : SDSS WD main-sequence binaries (Rebassa-Mansergas+, 2007)
J/A+A/621/A38 : Gaia catalogue of hot subluminous stars (Geier+, 2019)
B/cb : Cataclysmic Binaries, LMXBs, and related objects
(Ritter+, 2004)
Byte-by-byte Description of file: table[23].dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 23 A23 --- Name Source name (SDSSJHHMMSS.ss+DDMMSS.s)
25- 43 I19 --- GaiaDR2 Gaia DR2 source identifier of the primary
component
45- 63 I19 --- GaiaDR2s Gaia DR2 source identifier of the secondary
component
65- 69 F5.1 arcsec Sep Angular separation of the two components
71- 75 F5.3 mas dplx Parallax difference between the two
components
77- 81 F5.3 mas e_dplx Error on dplx
83- 87 F5.3 mas/yr dpm Proper motion difference between the two
components
89- 93 F5.3 mas/yr e_dpm Error on dpm
95-102 F8.1 AU A Projected orbital separation
104 A1 --- pCE [Y/N] Indicates if this is a post-common
envelope (pCE) binary system
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table4.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 22 A22 --- Name Source name
24- 42 I19 --- GaiaDR2 Gaia DR2 source identifier of the primary
component
44- 62 I19 --- GaiaDR2s Gaia DR2 source identifier of the secondary
component
64- 68 F5.1 arcsec Sep Angular separation of the two components
70- 74 F5.3 mas dplx Parallax difference between the two
components
76- 80 F5.3 mas e_dplx Error on dplx
82- 87 F6.3 mas/yr dpm Proper motion difference between the two
components
89- 93 F5.3 mas/yr e_dpm Error on dpm
95- 102 F8.1 AU A Projected orbital separation
104- 108 A5 --- Mult Information about any known multiplicity of
the sdB star (1)
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Note (1): Known multiplicity as follows:
Yes = known binarity of the sdB
No = no information
Known = the found companion is known
? = Existence of binary component is not confirmed with certainty
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Byte-by-byte Description of file: table5.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 10 A10 --- Name Source name
12- 30 I19 --- GaiaDR2 Gaia DR2 source identifier of the primary
component
32- 50 I19 --- GaiaDR2s Gaia DR2 source identifier of the secondary
component
52- 56 F5.1 arcsec Sep Angular separation of the two components
58- 62 F5.3 mas dplx Parallax difference between the two
components
64- 68 F5.3 mas e_dplx Error on dplx
70- 74 F5.3 mas/yr dpm Proper motion difference between the two
components
76- 80 F5.3 mas/yr e_dpm Error on dpm
82- 89 F8.1 AU A Projected orbital separation
91- 92 A2 --- Type Cataclysmic variable type (1)
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Note (1): Type as follows:
DN = dwarf novae
NL = nova like variable
CV = general CV
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History:
From electronic version of the journal
(End) Ana Fiallos [CDS] 24-May-2023