J/AJ/160/6 OSMOS & modspec RVs of 30 cataclysmic variables (Thorstensen, 2020)
Spectroscopic studies of 30 short-period cataclysmic variable stars and remarks
on the evolution and population of similar objects.
Thorstensen J.R.
<Astron. J., 160, 6 (2020)>
=2020AJ....160....6T 2020AJ....160....6T
ADC_Keywords: Stars, variable; Spectra, optical; Radial velocities;
Binaries, orbits; Parallaxes, trigonometric
Keywords: Cataclysmic variable stars ; Dwarf novae ; SU Ursae Majoris stars ;
WZ Sagittae stars ; Close binary stars ; Semi-detached binary stars
Abstract:
We present spectroscopy and orbital periods Porb for 30 apparently
nonmagnetic cataclysmic binaries with periods below ∼3hr, nearly all
of which are dwarf novae, mostly of the SU Ursae Majoris subclass. We
then turn to the evidence supporting the prediction that short-period
dwarf novae evolve toward longer periods after passing through a
minimum period-the "period bounce" phenomenon. Plotting data from the
literature reveals that for superhump period excess
ε=(Psh-Porb)/Porb below ∼0.015, the period appears to
increase with decreasing ε, agreeing at least qualitatively
with the predicted behavior. Next, motivated by the long (decadal)
outburst intervals of the WZ Sagittae subclass of short-period dwarf
novae, we ask whether there could be a sizable population of
"lurkers"-systems that resemble dwarf novae at minimum light, but
which do not outburst over accessible timescales (or at all) and
therefore do not draw attention to themselves. By examining the
outburst history of the Sloan Digital Sky Survey sample of Cataclysmic
Variables (CVs), which were selected by color and not by outburst, we
find that a large majority of the color-selected dwarf-nova-like
objects have been observed to outburst, and we conclude that
"lurkers," if they exist, are a relatively minor part of the CV
population.
Description:
All of the observations reported are from the Michigan-Dartmouth-MIT
(MDM) Observatory on Kitt Peak, Arizona, and nearly all are spectra.
Most are from the "modspec" spectrograph, mounted either on the
Hiltner 2.4m telescope or the McGraw-Hill 1.3m telescope. For nearly
all modspec observations the range was from 4310 to 7500Å. A few
observations were taken with a range from 4600 to 6800Å.
Our most recent observations are from the Ohio State Multi-Object
Spectrometer (OSMOS), mounted on the 2.4m and configured to give a
spectrum from 3975 to 6870Å.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 67 30 List of Cataclysmic Variables (CVs)
table2.dat 37 1603 Radial velocities
table3.dat 66 30 Fits to radial velocities
table4.dat 80 12 Candidate period bouncers
table5.dat 76 22 SDSS CVs without known outbursts
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See also:
I/337 : Gaia DR1 (Gaia Collaboration, 2016)
V/110 : Catalog of Cataclysmic Variables (Downes+ 2001)
V/123 : Catalog of Cataclysmic Variables (Downes+ 2001-2006)
J/A+AS/132/341 : ROSAT GPS optical identification (Motch+ 1998)
J/MNRAS/373/687 : Spectra of 5 faint cataclysmic variables (Southworth+, 2006)
J/AJ/134/185 : Cataclysmic variables from SDSS-DR5 (Szkody+, 2007)
J/AJ/136/2107 : Distances of cataclysmic variables (Thorstensen+, 2008)
J/MNRAS/384/1277 : Hα emission line sources from IPHAS (Witham+, 2008)
J/ApJ/696/870 : Catalina Real-time Transient Survey (CRTS) (Drake+, 2009)
J/A+A/524/A86 : Light curves of SDSS J003941.06+005427.5 (Southworth+, 2010)
J/MNRAS/402/436 : New Dwarf novae in SDSS, GALEX and astrom. cat. (Wils+,2010)
J/AJ/142/181 : CVs from SDSS. VIII. The final year (Szkody+, 2011)
J/AJ/144/81 : Spectro. & photometry of CV candidates (Thorstensen+, 2012)
J/MNRAS/421/2414 : Faint cataclysmic variables from SDSS (Woudt+, 2012)
J/MNRAS/443/3174 : 72 faint CV candidates in CRTS (Breedt+, 2014)
J/MNRAS/441/1186 : Cataclysmic variables from CRTS (Drake+, 2014)
J/ApJ/788/48 : X-ray through NIR photometry of NGC 2617 (Shappee+, 2014)
J/AJ/150/170 : Radial velocities of 7 cataclysmic binaries (Halpern+, 2015)
J/AJ/149/128 : RVs of 29 cataclysmic variables (Thorstensen+, 2015)
J/AJ/152/226 : RVs of 35 cataclysmic variables (Thorstensen+, 2016)
J/PASJ/68/65 : Superhumps in SU UMa-type dwarf novae (Kato+, 2016)
J/MNRAS/465/4968 : Cataclysmic variables observations (Hardy+, 2017)
J/PASJ/69/75 : Superhumps in SU UMa-type dwarf novae (Kato+, 2017)
J/AJ/155/247 : RVs of 6 X-ray cataclysmic binaries (Halpern+, 2018)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 15 A15 --- Name Star identification
17- 18 I2 h RAh Hour of Right Ascension (J2000) (1)
20- 21 I2 min RAm Minute of Right Ascension (J2000) (1)
23- 28 F6.3 s RAs Second of Right Ascension (J2000) (1)
30- 30 A1 --- DE- [-+]Sign of the Declination (J2000)(1)
31- 32 I2 deg DEd Degree of Declination (J2000) (1)
34- 35 I2 arcmin DEm Arcminute of Declination (J2000) (1)
37- 41 F5.2 arcsec DEs Arcsecond of Declination (J2000) (1)
43- 47 F5.2 mag Gmag [16.37/19.4] G band magnitude (1)
49- 54 F6.1 pc Dist [153/1400] Distance 1/parallax w/o corrections (1)
56- 61 F6.1 pc E_Dist [3/1200]? Upper uncertainty on Dist
63- 67 F5.1 pc e_Dist [3/450] Lower (or symmetric) uncertainty on Dist
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Note (1): Positions, mean G magnitudes, and distances from the GAIA
Data Release 1 (DR1; Gaia Collaboration+, 2016, I/337). Positions
are referred to the ICRS (essentially the reference frame for J2000),
and the catalog epoch (for proper motion corrections) is 2015. The
distances and their error bars are the inverse of the DR1 parallax
?DR1, and do not include any corrections for possible systematic
errors.
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 15 A15 --- Name Star identification
17- 29 F13.5 d JD [2451644/2458868] Barycentric Julian Date (UTC) of
mid-integration
31- 34 I4 km/s HRV [-261/196] Barycentric radial velocity of
H-α
36- 37 I2 km/s e_HRV [4/97] Uncertainty of radial velocity based on
counting statistics
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 15 A15 --- Name Star identification
17- 26 F10.4 d T0 [52437/58868] Epoch, Heliocentric Julian Date
JD-2400000 (1)
28- 29 I2 d e_T0 [2/20] Error in T0 (3)
31- 40 F10.8 d Per [0.05/0.11] Orbital period (2)
42- 43 I2 d e_Per [2/18] Error in P (3)
45- 45 A1 --- f_Per Flag on Per (4)
47- 49 I3 km/s K [22/108] Sinusoid fit parameter (2)
51- 52 I2 km/s e_K [4/23] Uncertainty in K (3)
54- 56 I3 km/s gamma [-97/90] Sinusoid fit parameter (γ) (2)
58- 59 I2 km/s e_gamma [3/16] Uncertainty in gamma (3)
61- 63 I3 --- N [20/127] Number of data points
65- 66 I2 km/s sigma [13/40] RMS residual of the fit (σ)
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Note (1): The epoch is chosen to be near the center of the time interval
covered by the data, and within one cycle of an actual observation.
Note (2): Parameters of least-squares sinusoid fits to the radial velocities,
of the form v(t)=γ+Ksin(2π(t?T0)/Per.
Note (3): Errors are given as the last N digits of the value.
Note (4): Flags as follows:
c = Because the cycle count between runs is unknown, the period given
here is the weighted average of periods derived from the individual
observing runs. The remaining parameters are from a fit to the
entire data set (5 occurrences)
d = The precise period given reflects a likely choice of cycle count
between observing runs; see discussion in text (1 occurrence)
e = The period given is the most likely precise period, but other
choices of cycle count between runs have similar likelihood and give
slightly different periods; see text (1 occurrence)
f = Daily cycle count inferred using the known superhump period
(4 occurrences)
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 25 A25 --- Name Candidate identification
27- 28 I2 h RAh [0/22] Hour of Right Ascension (J2000)
30- 31 I2 min RAm Minute of Right Ascension (J2000)
33- 37 F5.2 s RAs Second of Right Ascension (J2000)
39- 39 A1 --- DE- [-+] Sign of the Declination (J2000)
40- 41 I2 deg DEd Degree of Declination (J2000)
43- 44 I2 arcmin DEm Arcminute of Declination (J2000)
46- 49 F4.1 arcsec DEs Arcsecond of Declination (J2000)
51- 56 F6.4 --- epsilon [0.004/0.02] Fractional superhump period excess
(ε)
58- 63 F6.4 --- q [0.02/0.07] Mass ratio
65- 71 F7.5 d Porb [0.05/0.07] Orbital period
73- 76 F4.1 min Porb-min [84.2/92.4] Orbital period
78- 80 A3 --- Refs References (1)
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Note (1): References as follows:
T = This work, ans Pala+, 2018MNRAS.481.2523P 2018MNRAS.481.2523P
1 = Kato+, 2009PASJ...61S.395K 2009PASJ...61S.395K
3 = Kato+, 2012PASJ...64...21K 2012PASJ...64...21K
5 = Kato+, 2014PASJ...66...30K 2014PASJ...66...30K
7 = Kato+, 2015PASJ...67..105K 2015PASJ...67..105K
8 = Kato+, 2016, J/PASJ/68/65
9 = Kato+, 2017, J/PASJ/69/75
10 = Kato+, 2020PASJ...72...14K 2020PASJ...72...14K
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Byte-by-byte Description of file: table5.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 24 A24 --- SDSS SDSS identification of the star
(JHHMMSSss+DDMMSSs)
26- 26 I1 --- r_SDSS [1/8] Paper in which the object was identified (1)
28- 31 A4 --- Type Type (2)
33- 39 A7 min Porb Orbital period
41- 41 A1 --- f_Porb Flag on Porb (3)
43- 43 A1 --- r_Porb Reference for Porb (4)
45- 49 F5.2 mag gmag [18.5/21.9] SDSS g' band magnitude from discovery
papers
51- 55 F5.2 mag Gmag [17.9/20.9]? Gaia DR2 G band magnitude
57- 63 F7.4 mas Plx [-1.34/4.46]? Gaia DR2 Parallax
65- 70 F6.4 mas e_Plx [0.16/1.96]? Uncertainty in Plx
72- 76 F5.2 mas/yr PM [4.61/78.9]? Total proper motion (5)
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Note (1): References as follows:
1 = Szkody+, 2002AJ....123..430S 2002AJ....123..430S
2 = Szkody+, 2003AJ....126.1499S 2003AJ....126.1499S
3 = Szkody+, 2004AJ....128.1882S 2004AJ....128.1882S
4 = Szkody+, 2005AJ....129.2386S 2005AJ....129.2386S
5 = Szkody+, 2006AJ....131..973S 2006AJ....131..973S
6 = Szkody+, 2007, J/AJ/134/185
7 = Szkody+, 2009AJ....137.4011S 2009AJ....137.4011S
8 = Szkody+, 2011, J/AJ/142/181
Note (2): Types as follows:
DN-2 = Dwarf Novae with apparent late-type secondary contributions,
which usually have orbital periods above ∼5hr (4 occurrences)
DN-W = Dwarf Novae showing a white dwarf contribution, which must have
low disk luminosities and often have orbital periods below 3hr
(10 occurrences)
DN = All others Dwarf Novae (8 occurrences)
Note (3): Flag as follows:
d = Two alias periods are possible (1 occurrence)
Note (4): References as follows :
1 = Southworth+, 2010, J/A+A/524/A86
2 = Southworth+, 2008MNRAS.391..591S 2008MNRAS.391..591S
3 = Thorstensen+, 2015, J/AJ/149/128
4 = Woudt+, 2012, J/MNRAS/421/2414
5 = E. Breedt, private communication, from VLT/FORS velocities
6 = Southworth+, 2006, J/MNRAS/373/687
7 = Littlefair+, 2008MNRAS.388.1582L 2008MNRAS.388.1582L
8 = Southworth+, 2007MNRAS.382.1145S 2007MNRAS.382.1145S
9 = Dillon+, 2008MNRAS.386.1568D 2008MNRAS.386.1568D
Note (5): Total proper motion from pmRA, pmDE reported in Gaia DR2.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Coralie Fix [CDS], 30-Sep-2020