J/A+A/631/A104 PSR J1023+0038 VLT, XM and Swift observations (Baglio+, 2019)
Peering at the outflow mechanisms in the transitional pulsar PSR J1023+0038:
simultaneous VLT, XMM-Newton, and Swift high-time resolution observations.
Baglio M.C., Vincentelli F., Campana S., Coti Zelati F., D'Avanzo P.,
Burderi L., Casella P., Papitto A., Russell D.M.
<Astron. Astrophys. 631, A104 (2019)>
=2019A&A...631A.104B 2019A&A...631A.104B (SIMBAD/NED BibCode)
ADC_Keywords: Pulsars ; X-ray sources ; Infrared sources ; Optical
Keywords: stars: jets - stars: neutron - X-rays: binaries
Abstract:
We report on a simultaneous near-infrared, optical, and X-ray campaign
performed in 2017 with the XMM-Newton and Swift satellites and the
HAWK-I instrument mounted on the Very Large Telescope (VLT) on the
transitional millisecond pulsar PSR J1023+0038. Near-infrared
observations were performed in fast-photometric mode (0.5s exposure
time) in order to detect any fast variation of the flux and correlate
this with the optical and X-ray light curves. The optical light curve
shows the typical sinusoidal modulation at the system orbital period
(4.75hr). No significant flaring or flickering is found in the
optical, nor any signs of transitions between active and passive
states. On the contrary, the near-infrared light curve displays a
bimodal behaviour, showing strong flares in the first part of the
curve, and an almost flat trend in the rest. The X-ray light curves
instead show a few low-high mode transitions, but no flaring activity
is detected. Interestingly, one of the low-high mode transitions
occurs at the same time as the emission of an infrared flare. This can
be interpreted in terms of the emission of an outflow or a jet: the
infrared flare could be due to the evolving spectrum of the jet, which
possesses a break frequency that moves from higher (near-infrared) to
lower (radio) frequencies after the launching, which has to occur at
the low-high mode transition. We also present the cross-correlation
function between the optical and near-infrared curves. The
near.infrared curve is bimodal, therefore we divided it into two parts
(flaring and quiet). While the cross-correlation function of the quiet
part is found to be flat, the function that refers to the flaring part
shows a narrow peak at 10s, which indicates a delay of the
near-infrared emission with respect to the optical. This lag can be
interpreted as reprocessing of the optical emission at the light
cylinder radius with a stream of matter spiraling around the system
due to a phase of radio ejection. This strongly supports a different
origin of the infrared flares that are observed for PSR J1023+0038
with respect to the optical and X-ray flaring activity that has been
reported in other works on the same source.
Description:
We collected NIR (J-band, 1.2um) high time-resolution data with the
HAWK-I instrument mounted on the VLT, UT-4/Yepun, on 2017 June 10.
XMM-Newton observed J1023 on 2017 June 9.
Swift XRT started observing J1023 on 2017 June 9 at 22:34:04. The XRT
was operated in photon-counting mode (2.5s time resolution). The
observation lasted 7.0ks, split into five consecutive orbits.
The XMM-Newton Optical Monitor (OM) observed J1023 starting on June 9
at 22:32:27 UTC in fast mode, using the B filter (central effective
wavelength of 450 nm).
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 = V* AY Sex
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File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
om.dat 53 2119 Light curve obtained with XMM-OM reported in
Fig. 1 of the paper
hawk-i.dat 47 15169 Light curve obtained with VLT/HAWK-I reported in
Fig. 2 of the paper
xrt.dat 47 696 Light curve obtained with Swift/XRT reported in
Fig. 1 of the paper
rgs2.dat 39 171 Light curve obtained with XMM-RGS reported in
Fig. 1 of the paper
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Byte-by-byte Description of file: om.dat
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Bytes Format Units Label Explanations
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1- 13 F13.7 s Time Time after 2017-06-10 00:00:00 UT
17- 33 F17.15 mJy Flux Flux of the target
37- 53 F17.15 mJy e_Flux Error on the flux
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Byte-by-byte Description of file: hawk-i.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 17 F17.11 s Time Time after 2017-06-10 00:00:00 UT
20- 31 F12.10 mJy Flux Flux of the target
36- 47 F12.10 mJy e_Flux Error on the flux
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Byte-by-byte Description of file: xrt.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 21 F21.15 s Time Time after 2017-06-10 00:00:00 UT
23- 32 F10.8 ct/s CRate Counts per second measured for the target
38- 47 F10.8 ct/s e_CRate Error on the counts per second measured
for the target
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Byte-by-byte Description of file: rgs2.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 8 F8.2 s Time Time after 2017-06-10 00:00:00 UT
10- 23 F14.11 ct/s CRate Counts per second measured for the target
28- 39 F12.10 ct/s e_CRate Error on the counts per second measured
for the target
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Acknowledgements:
Maria Cristina Baglio, mcb19(at)nyu.edu
(End) Patricia Vannier [CDS] 15-Oct-2019