First X-ray observations of the intermediate polar SWIFT J183221.56-162724.257
ATel #15388; I. J. Lima (Conicet/IAFE/UBA, Argentina), G. J. M. Luna (Conicet/IAFE/UBA, Argentina), C. V. Rodrigues (INPE, Brazil), A. S. Oliveira (UNIVAP, Brazil), F. J. Jablonski (INPE, Brazil), D. C. Souza (UNIVAP, Brazil), F. F. Marques (INPE, Brazil), N. Palivanas (UNIVAP, Brazil)
on 20 May 2022; 20:52 UT
Credential Certification: Isabel de Jesus Lima (isabellima01@gmail.com)
Subjects: X-ray, Cataclysmic Variable, Variables
We report on the first X-ray detection of SWIFT J183221.56-162724.25 (J1832; Gaia DR2 4102856333775127296). This source was recently discovered and classified as the first eclipsing stream-fed intermediate polar (IP) based on optical observations (Beuermann K. et al. 2022, A&A, 657, A101). There are about 150 known IPs (Mukai's IP catalog), 3 systems accretes via stream and 5 exhibit deep eclipses. Therefore, the combination of deep eclipse and stream-fed makes J1832 a unique system. We obtained X-ray observations with SWIFT-XRT in PC mode on 2022 Apr 26 (Obsid: 00015137001). The total exposure time was 4563 s and the source was detected with a S/R of 5.8 with a count rate of 0.013 +- 0.002 counts/s. The observations cover orbital phase from 0.2 to 0.8, considering the linear ephemeris proposed by Beuermann et al. (2022). So the observations were probably obtained outside the eclipse. The spectra can be fitted using an absorbed with thermal APEC component. We obtained a Hydrogen columnar density, N(H), of 0.47(-0.38 +0.89)e22 cm^-2. This value is consistent with N(H) x A(V) relation of Zhu H. et al. 2017, MNRAS, 471, 3494, considering A(V) = 1.285 coming from 3D extinction map (http://www.galextin.org, Amôres E. B., et al., 2021, MNRAS, 508, 1788). We also find a temperature around 13 KeV. The estimated unabsorbed flux is (1.2 +- 0.1)e-12 ergs/s/cm^2. Using the mean distance of 1569 pc proposed by Beuermann et al. (2022), which is within the Gaia EDR3 limits (Bailer-Jones et al. 2021, AJ, 161, 147), the luminosity of J1832 is 3.6e+32 ergs/s, typical of X-ray emission from magnetic accreting WDs (Mukai K., 2017, PASP, 129). The UVOT instrument observed the source during 1.1 ks in UVW1 filter. Its Vega magnitude was 19.05 +- 0.20 (statistical) +- 0.03 (systematic). We would like to thank the Swift team for quick planning of the observations.
Mukai's IP catalog
