J/A+A/690/A344 Optical spectra of PSR J1023+0038 (Messa+, 2024)
High temporal resolution optical spectroscopic observations of the transitional
millisecond pulsar PSR J1023+0038.
Messa M.M., D'Avanzo P., Coti Zelati F., Baglio M.C., Campana S.
<Astron. Astrophys. 690, A344 (2024)>
=2024A&A...690A.344M 2024A&A...690A.344M (SIMBAD/NED BibCode)
ADC_Keywords: Binaries, X-ray; Spectra, optical
Keywords: accretion, accretion discs - stars: neutron - X-rays: binaries
Abstract:
Transitional millisecond pulsars (tMSPs) represent a dynamic category
of celestial sources that establish a crucial connection between
low-mass X-ray binaries and millisecond radio pulsars. These systems
exhibit transitions from rotation-powered states to accretion-powered
ones and vice versa, highlighting the tight evolutionary link expected
by the so-called recycling scenario. In their active phase, these
sources manifest two distinct emission modes named high and low,
occasionally punctuated by sporadic flares. Here, we present
high-time-resolution spectroscopic observations of the binary tMSP
J1023+0038, in the sub-luminous disc state. This is the first
short-timescale (∼1 min) optical spectroscopic campaign ever conducted
on a tMSP. The campaign was carried out over the night of June 10,
2021 using the Gran Telescopio Canarias. The optical continuum shows
erratic variability, without clear evidence of high and low modes or
of orbital modulation. Besides, the analysis of these
high-temporal-cadence spectroscopic observations reveals, for the
first time, evidence for a significant (up to a factor of ∼2)
variability in the emission line properties (equivalent width and full
width half maximum) over a timescale of minutes. Intriguingly, the
variability episodes observed in the optical continuum and in the
emission line properties seem uncorrelated, making their origin
unclear.
Description:
We present 87 reduced spectra of PSR J1023+0038.
Every spectrum file (ASCII) is named PSRJ1023+0038GTC20210610_speXX.dat,
where XX goes from 01 to 87. Each spectrum file has the same data
structure: Wavelength (Å), Flux Density (mJy).
Objects:
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RA (2000) DE Designation(s)
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10 23 47.68 +00 38 41.0 PSR J1023+0038 = 2XMM J102347.6+003841
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
log.dat 65 87 Information on the 87 reduced spectra
sp/* . 87 Individual spectra
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See also:
J/A+A/591/A101 : PSRJ1023+0038 + XSSJ12270-4859 VRi polarimetry (Baglio+ 2016)
J/A+A/631/A104 : PSRJ1023+0038 VLT, XM and Swift observations (Baglio+, 2019)
Byte-by-byte Description of file: log.dat
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Bytes Format Units Label Explanations
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1- 2 I2 --- ID Number of the spectrum
4- 6 A3 --- Tel [GTC] Name of the telescope
8- 13 A6 --- Inst [OSIRIS] Name of the instrument
15- 25 F11.5 d MJDstart Starting date of the spectra (MJD)
27- 28 I2 s Texp [20] Exposure time of the single spectrum
30- 65 A36 --- FileName Name of the spectrum file in subdirectory sp
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Byte-by-byte Description of file: sp/*
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Bytes Format Units Label Explanations
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1- 7 F7.2 0.1nm lambda Wavelength
9- 22 F14.11 mJy S Flux density
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History:
From Marco Massa, marco.messa(at)inaf.it
Acknowledgements:
This research is based on observations made with the GTC telescope, in
the Spanish Observatorio del Roque de los Muchachos of the Instituto
de Astrofisica de Canarias, under Director's Discretionary Time
(Pr. ID: GTC2021-181).
(End) Patricia Vannier [CDS] 29-Jul-2024