J/A+A/690/A68 New sample of Galactic white dwarfs (Sidharth+, 2024)
Detection of a new sample of Galactic white dwarfs in the direction of the
Small Magellanic Cloud.
Sidharth A.V., Shridharan B., Mathew B., Devaraj A., Cysil T.B.,
Stalin C.S., Arun R., Bhattacharyya S., Kartha S.S., Robin T.
<Astron. Astrophys. 690, A68 (2024)>
=2024A&A...690A..68S 2024A&A...690A..68S (SIMBAD/NED BibCode)
ADC_Keywords: Milky Way ; Stars, white dwarf ; Photometry, ultraviolet
Keywords: techniques: photometric - binaries: general -
Hertzsprung-Russell and C-M diagrams - white dwarfs -
ultraviolet: stars -
Abstract:
In this study, we demonstrate the efficacy of the Ultraviolet Imaging
Telescope (UVIT) in identifying and characterizing white dwarfs (WDs)
within the Milky Way Galaxy. Leveraging the UVIT point source
catalogue towards SMC and crossmatching with Gaia DR3 data, we
identified 43 single WDs (37 new detections), 13 new WD+main sequence
(MS) candidates and 161 UV bright MS stars by analysing their Spectral
Energy Distributions (SED). Using the WD evolutionary models, we
determine the masses, effective temperatures, and cooling ages of
these identified WDs. Masses of these WDs range from 0.2 to
1.3M☉ and effective temperatures (Teff) between 10000K to
15000K, with cooling ages spanning 0.1 to 2Gyr. Notably, we detect
hotter WDs compared to literature values, which is attributed to the
sensitivity of UVIT. Furthermore, we report the detection of 20 new
extremely low-mass (ELM) candidates from our analysis. Future
spectroscopic studies of the ELM candidates will help us understand
the formation scenarios of these exotic objects. Despite limitations
in Gaia DR3 distance measurements for optically faint WDs, we provide
a crude estimate of the WD space density within 1kpc as
1.3x10-3pc-3, which is higher than previous estimates in the
literature. Our results underscore the instrumental capabilities of
UVIT and anticipate the forthcoming UV missions like INSIST for
systematic WD discovery. Our methodology sets a precedent for future
analyses in other UVIT fields to find more WDs and perform
spectroscopic studies to verify their candidacy.
Description:
We provide a catalogue of 43 single white dwarfs (table1.dat)
identified in this study that includes their AstroSat/UVIT magnitudes
and derived stellar parameters such as Teff, logg, Cooling age, and
mass. Additionally, the catalogue of 13 WD+MS binaries (table2.dat)
contains similar information for the WD+MS binaries identified in this
study. Furthermore, we have provided a catalogue (tableA1.dat)
encompassing all 273 sources studied in this work, including their
UVIT and Gaia magnitudes. This catalogue also includes the object
types and IDs of objects studied in previous literature provided by
SIMBAD. Lastly, tableB1.dat provides a catalogue of UV bright MS stars
identified in this study.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 231 43 List of the 43 single white dwarfs identified
in the present study
table2.dat 254 13 List of the 13 WD+MS candidates identified from
the present study
tablea1.dat 627 273 List of 273 sources with their UVIT magnitudes
used in this study with literature
(SIMBAD) match
tableb1.dat 162 161 List of the 161 UV bright MS stars identified
from the present study
--------------------------------------------------------------------------------
See also:
I/355 : Gaia DR3 Part 1. Main source (Gaia Collaboration, 2022)
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 8 A8 --- --- [Gaia DR3]
10- 28 I19 --- GaiaDR3 Unique source identifier provided by Gaia DR3
30- 37 F8.5 deg RAdeg Right Ascension (J2000)
39- 47 F9.5 deg DEdeg Declination (J2000)
49- 55 F7.2 pc Dist Distance
57- 63 F7.2 pc b_Dist Lower limit of distance
65- 71 F7.2 pc B_Dist Upper limit of distance
73- 80 F8.3 mag N263Mmag ?=9999 Magnitude in UVIT/N263M filter
82- 89 F8.3 mag e_N263Mmag ?=9999 Error in Magnitude in UVIT/N263M filter
91- 98 F8.3 mag N245Mmag ?=9999 Magnitude in UVIT/N245M filter
100-107 F8.3 mag e_N245Mmag ?=9999 Error in Magnitude in UVIT/N245M filter
109-116 F8.3 mag N279Nmag ?=9999 Magnitude in UVIT/N279N filter
118-125 F8.3 mag e_N279Nmag ?=9999 Error in Magnitude in UVIT/N279N filter
127-134 F8.3 mag F172Mmag ?=9999 Magnitude in UVIT/F172M filter
136-143 F8.3 mag e_F172Mmag ?=9999 Error in Magnitude in UVIT/F172M filter
145-152 F8.3 mag F169Mmag ?=9999 Magnitude in UVIT/F169M filter
154-161 F8.3 mag e_F169Mmag ?=9999 Error in Magnitude in UVIT/F169M filter
163-170 F8.3 mag F154Wmag ?=9999 Magnitude in UVIT/F154W filter
172-179 F8.3 mag e_F154Wmag ?=9999 Error in Magnitude in UVIT/F154W filter
181-188 F8.3 mag N219Mmag ?=9999 Magnitude in UVIT/N219M filter
190-197 F8.3 mag e_N219Mmag ?=9999 Error in Magnitude in UVIT/N219M filter
199-203 I5 K Teff Effective temperature of the White Dwarf
205-208 F4.2 [cm/s2] logg Surface gravity of the White Dwarf
210-216 F7.2 Gyr CoolAge Cooling age of the White Dwarf in Gyr
218-224 F7.2 Msun Mass Mass of the White Dwarf in solar mass
226-231 A6 --- Remarks Remark if the WD is an ELM or not?
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 8 A8 --- --- [Gaia DR3]
10- 28 I19 --- GaiaDR3 Unique source identifier provided by
Gaia DR3
30- 37 F8.5 deg RAdeg Right Ascension (J2000)
39- 47 F9.5 deg DEdeg Declination (J2000)
49- 55 F7.2 pc Dist Distance
57- 62 F6.2 pc b_Dist Lower limit of Distance
64- 70 F7.2 pc B_Dist Upper limit of distance
72- 79 F8.3 mag N263Mmag ?=9999 Magnitude in UVIT/N263M filter
81- 88 F8.3 mag e_N263Mmag ?=9999 Error in Magnitude in UVIT/N263M
filters
90- 95 F6.3 mag N245Mmag ?=9999 Magnitude in UVIT/N245M filter
97-101 F5.3 mag e_N245Mmag ?=9999 Error in Magnitude in UVIT/N245M
filters
103-110 F8.3 mag N279Nmag ?=9999 Magnitude in UVIT/N279N filter
112-119 F8.3 mag e_N279Nmag ?=9999 Error in Magnitude in UVIT/N279N
filters
121-128 F8.3 mag F172Mmag ?=9999 Magnitude in UVIT/F172M filter
130-137 F8.3 mag e_F172Mmag ?=9999 Error in Magnitude in UVIT/F172M
filters
139-146 F8.3 mag F169Mmag ?=9999 Magnitude in UVIT/F169M filter
148-155 F8.3 mag e_F169Mmag ?=9999 Error in Magnitude in UVIT/F169M
filters
157-164 F8.3 mag F154Wmag ?=9999 Magnitude in UVIT/F154W filter
166-173 F8.3 mag e_F154Wmag ?=9999 Error in Magnitude in UVIT/F154W
filters
175-182 F8.3 mag N219Mmag ?=9999 Magnitude in UVIT/N219M filter
184-191 F8.3 mag e_N219Mmag ?=9999 Error in Magnitude in UVIT/N219M
filters
193-196 I4 K TeffMS Effective temperature of the MS component
198-200 F3.1 [cm/s2] loggMS Surface gravity of the MS component
202-205 I4 K b_TeffMS Lower limit of effective temperature of
the MS component
207-210 I4 K B_TeffMS Upper limit of effective temperature of
the MS component
212-215 F4.2 [cm/s2] b_loggMS Lower limit of surface gravity of
the MS component
217-220 F4.2 [cm/s2] B_loggMS Upper limit of surface gravity of
the MS component
222-226 I5 K TeffWD Effective temperature of the WD component
228-231 F4.2 --- loggWD Surface gravity of the WD component
233-239 F7.2 Gyr CoolgAge Cooling age of the White Dwarf in Gyr
241-247 F7.2 Msun Mass Mass of the White Dwarf in solar mass
249-254 A6 --- Remarks Remark if the WD is an ELM or not?
--------------------------------------------------------------------------------
Byte-by-byte Description of file: tablea1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 8 A8 --- --- [Gaia DR3]
10- 28 I19 --- GaiaDR3 Unique source identifier provided by Gaia DR3
30- 47 F18.15 deg RAdeg Right Ascension (J2000)
49- 66 F18.14 deg DEdeg Declination (J2000)
68- 86 F19.14 pc Dist Distance
88-106 F19.14 pc b_Dist Lower limit of distance
108-126 F19.14 pc B_Dist Upper limit of distance
128-145 F18.15 mag Gmag ?=9999 Magnitude in Gaia DR3 G band filter
147-166 F20.18 mag e_Gmag ?=9999 Error in magnitude in Gaia DR3
G band filter
168-185 F18.15 mag Bpmag ?=9999 Magnitude in Gaia DR3 BP band filter
187-206 F20.18 mag e_Bpmag ?=9999 Error in Magnitude in Gaia DR3
BP band filter
208-225 F18.15 mag Rpmag ?=9999 Magnitude in Gaia DR3 RP band filter
227-246 F20.18 mag e_Rpmag ?=9999 Error in Magnitude in Gaia DR3
RP band filter
248-267 F20.15 mag N263Mmag ?=9999 Magnitude in UVIT/N263M filter
269-291 F23.18 mag e_N263Mmag ?=9999 Error in Magnitude in UVIT/N263M filter
293-312 F20.15 mag N245Mmag ?=9999 Magnitude in UVIT/N245M filter
314-336 F23.18 mag e_N245Mmag ?=9999 Error in Magnitude in UVIT/N245M filter
338-357 F20.15 mag N279Nmag ?=9999 Magnitude in UVIT/N279N filter
359-381 F23.18 mag e_N279Nmag ?=9999 Error in Magnitude in UVIT/N279N filter
383-402 F20.15 mag F172Mmag ?=9999 Magnitude in UVIT/F172M filter
404-426 F23.18 mag e_F172Mmag ?=9999 Error in Magnitude in UVIT/F172M filter
428-447 F20.15 mag F169Mmag ?=9999 Magnitude in UVIT/F169M filter
449-471 F23.18 mag e_F169Mmag ?=9999 Error in Magnitude in UVIT/F169M filter
473-492 F20.15 mag F154Wmag ?=9999 Magnitude in UVIT/F154W filter
494-516 F23.18 mag e_F154Wmag ?=9999 Error in Magnitude in UVIT/F154W filter
518-537 F20.15 mag N219Mmag ?=9999 Magnitude in UVIT/N219M filter
539-561 F23.18 mag e_N219Mmag ?=9999 Error in Magnitude in UVIT/N219M filter
563-592 A30 --- MainId Object ID given by SIMBAD
594-612 A19 --- r_MainId Reference bib code
614-627 A14 --- MainType Object type given by SIMBAD
--------------------------------------------------------------------------------
Byte-by-byte Description of file: tableb1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 8 F8.5 deg RAdeg Right Ascension (J2000)
10- 18 F9.5 deg DEdeg Declination (J2000)
20- 26 F7.2 pc Dist Distance
28- 35 F8.3 mag N263Mmag ?=9999 Magnitude in UVIT/N263M filter
37- 44 F8.3 mag e_N263Mmag ?=9999 Error in Magnitude in UVIT/N263M filter
46- 53 F8.3 mag N245Mmag ?=9999 Magnitude in UVIT/N245M filter
55- 62 F8.3 mag e_N245Mmag ?=9999 Error in Magnitude in UVIT/N245M filter
64- 71 F8.3 mag N279Nmag ?=9999 Magnitude in UVIT/N279N filter
73- 80 F8.3 mag e_N279Nmag ?=9999 Error in Magnitude in UVIT/N279N filter
82- 89 F8.3 mag F172Mmag ?=9999 Magnitude in UVIT/F172M filter
91- 98 F8.3 mag e_F172Mmag ?=9999 Error in Magnitude in UVIT/F172M filter
100-107 F8.3 mag F169Mmag ?=9999 Magnitude in UVIT/F169M filter
109-116 F8.3 mag e_F169Mmag ?=9999 Error in Magnitude in UVIT/F169M filter
118-125 F8.3 mag F154Wmag ?=9999 Magnitude in UVIT/F154W filter
127-134 F8.3 mag e_F154Wmag ?=9999 Error in Magnitude in UVIT/F154W filter
136-143 F8.3 mag N219Mmag ?=9999 Magnitude in UVIT/N219M filter
145-152 F8.3 mag e_N219Mmag ?=9999 Error in Magnitude in UVIT/N219M filter
154-158 I5 K Teff Effective temperature of the MS star
160-162 F3.1 [cm/s2] logg Surface gravity of the MS star
--------------------------------------------------------------------------------
Acknowledgements:
A.V. Sidharth, sidharthnarayanan17(at)gmail.com
(End) Patricia Vannier [CDS] 08-Aug-2024