J/MNRAS/471/3028 UVIT and GALEX count rates (Rahna+, 2017)
Investigating the in-flight performance of the UVIT payload on AstroSat.
Rahna P.T., Murthy J., Safonova M., Sutaria F., Gudennavar S.B.,
Bubbly S.G.
<Mon. Not. R. Astron. Soc., 471, 3028-3035 (2017)>
=2017MNRAS.471.3028R 2017MNRAS.471.3028R (SIMBAD/NED BibCode)
ADC_Keywords: Stars, standard ; Photometry, ultraviolet
Keywords: instrumentation: detectors - techniques: photometric -
ultraviolet: general
Abstract:
We have studied the performance of the Ultraviolet Imaging Telescope
payload on AstroSat and derived a calibration of the far-ultraviolet
(FUV) and near-ultraviolet (NUV) instruments on board. We find that
the sensitivity of both the FUV and NUV channels is as expected from
ground calibrations, with the FUV effective area about 35 per cent and
the NUV effective area about the same as that of GALEX. The point
spread function of the instrument is on the order of 1.2-1.6''. We
have found that pixel-to-pixel variations in the sensitivity are less
than 10 per cent with spacecraft motion compensating for most of the
flat-field variations. We derived a distortion correction but
recommend that it be applied post-processing as part of an astrometric
solution.
Description:
AstroSat was conceived as India's first dedicated astronomy satellite
with three X-ray instruments and a UV payload (UVIT)
UVIT consists of two identical Ritchey-Chretien telescopes with
intensified CMOS detectors: one telescope with a CsI detector (FUV
channel) with the other telescope feeding two detectors through a
dichroic.
We have performed an independent evaluation of the performance of the
UVIT FUV and NUV instruments based on their in-flight performance.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 65 3262 Photometry of stars used in the calibration
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 4 I4 --- Star [1/2694] Star identification number, within
the detector (FUV or NUV)
6- 13 F8.4 deg RAdeg Right ascension (J2000)
15- 22 F8.4 deg DEdeg Declination (J2000)
24- 30 F7.3 ct/s GALEXCR GALEX count rate
32- 40 F9.3 s TexpG GALEX exposure time
42- 49 F8.3 ct/s UVITCR UVIT count rate
51- 58 F8.2 s TexpU UVIT exposure time
60- 61 A2 --- Filt Filter (F1, F2, F3, F5 or F6)
63- 65 A3 --- Det Detector (FUV or NUV)
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 26-May-2020