J/ApJ/904/49 4FGLJ0407.7-5702 optical spectroscopy & light curve (Miller+, 2020)
A New Candidate Transitional Millisecond Pulsar in the Subluminous Disk State;
4FGL J0407.7-5702.
Miller J.M., Swihart S.J., Strader J., Urquhart R., Aydi E., Chomiuk L.,
Dage K.C., Kawash A., Shishkovsky L., Sokolovsky K.V.
<Astrophys. J., 904, 49 (2020)>
=2020ApJ...904...49M 2020ApJ...904...49M
ADC_Keywords: Stars, neutron; Spectra, optical; Photometry, VRI
Keywords: Neutron stars ; Gamma-rays
Abstract:
We report the discovery of a variable optical and X-ray source within
the error ellipse of the previously unassociated Fermi Large Area
Telescope γ-ray source 4FGLJ0407.7-5702. A 22ks observation from
XMM-Newton/European Photon Imaging Camera (EPIC) shows an X-ray light
curve with rapid variability and flaring. The X-ray spectrum is well
fit by a hard power law with Γ=1.7. Optical photometry taken
over several epochs is dominated by aperiodic variations of moderate
amplitude. Optical spectroscopy with Southern Astrophysical Research
(SOAR) and Gemini reveals a blue continuum with broad and
double-peaked H and He emission, as expected for an accretion disk
around a compact binary. Overall, the optical, X-ray, and γ-ray
properties of 4FGLJ0407.7-5702 are consistent with a classification as
a transitional millisecond pulsar in the subluminous disk state. We
also present evidence that this source is more distant than other
confirmed or candidate transitional millisecond pulsar binaries, and
that the ratio of X-ray to γ-ray flux is a promising tool to
help identify such binaries, indicating that a more complete census
for these rare systems is becoming possible.
Description:
We obtained optical spectroscopy with the Goodman Spectrograph on the
Southern Astrophysical Research (SOAR) telescope on parts of six
different nights from 2019 November 6 to 2020 January 17. In all cases
we used a 400l/mm grating with a 0.95" slit, giving a resolution of
about 5.6Å (FWHM). Some of the spectra were obtained with a
wavelength range of ∼3820-7850Å, while others used a central
wavelength with coverage about 1000Å redder. Each spectrum had an
exposure time of 1500s.
We also obtained several spectra with Gemini/Gemini Multi-Object
Spectrograph-South (GMOS-S; Program ID: GS-2019B-FT-111) on the nights
of 2019 December 30 and 31. On each night three 1200s exposures were
taken. The R400 grating and a 1.0" slit together yielded an FWHM
resolution of about 7.2Å over the wavelength range ∼4500-9150Å.
We observed the source with SOAR/Goodman in imaging mode on 2019
December 16 and again on 2020 January 12. On 2019 December 16, which
had seeing around 1", we took a series of 180s exposures, alternating
between the Sloan Digital Sky Survey g' and i' filters, while on the
second, brighter night, with a median seeing of 0.8", we only observed
in i', with a frame time of 120s.
Objects:
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RA (2000) DE Designation(s)
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04 07 30.2 -57 00 24 4FGL J0407.7-5702 = 4FGL J0407.7-5702
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
fig7.dat 16 1594 Rectified coadded SOAR optical spectra of
4FGL J0407.7-5702
fig8.dat 36 225 SOAR g' and i' optical photometry of
4FGL J0407.7-5702, taken on 2019 December 17
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See also:
II/357 : The Dark Energy Survey (DES): Data Release 1 (Abbott+, 2018)
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
J/MNRAS/397/1177 : Swift-XRT observations of GRBs (Evans+, 2009)
J/A+A/588/A103 : Second ROSAT all-sky survey source catalog (Boller+, 2016)
J/A+A/594/A116 : HI4PI spectra and column density maps (HI4PI team+, 2016)
J/ApJ/831/89 : Eclipsing LMXB at center of 3FGL J0427.9-6704 (Strader+, 2016)
J/ApJ/866/83 : Opt/NIR obs. 1FGLJ1417.7-4407 neutron star (Swihart+, 2018)
J/ApJ/872/42 : Opt. spectroscopy redback ms pulsar binaries (Strader+, 2019)
J/AJ/158/16 : Identification of RR Lyrae stars from DES (Stringer+, 2019)
Byte-by-byte Description of file: fig7.dat
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Bytes Format Units Label Explanations
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1- 4 I4 0.1nm Wave [4001/7151] Wavelength
6- 16 E11.6 --- Flux [0.73/2.11] Rectified flux (10-13erg/s/cm2)
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Byte-by-byte Description of file: fig8.dat
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Bytes Format Units Label Explanations
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1- 3 A3 --- Obs.M Month of the observation (1)
5- 20 F16.8 d BJD [2458834/2458862] Barycentric Julian date of
observation
22- 28 F7.4 mag omag [19.6/20.8] Apparent Magnitude in Band
30- 34 F5.3 mag e_omag [0.009/0.03] Uncertainty in omag
36- 36 A1 --- Filt SDSS filter used; g' or i'
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Note (1): Months as follows:
Dec = 2019 Dec 17
Jan = 2020 Jan 13
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History:
From electronic version of the journal
(End) Prepared by [AAS], Coralie Fix [CDS], 15-Mar-2022