Magnetic accretion in cataclysmic variables: SW~Sextantis stars and a search for new objects

• Grant number: 18/05420-1
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate
• Effective date (Start): October 30, 2018
• Effective date (End): October 24, 2019
• Field of knowledge: Physical Sciences and Mathematics - Astronomy - Stellar Astrophysics
• Principal Investigator: Cláudia Vilega Rodrigues
• Grantee: Isabel de Jesus Lima
• Supervisor: Paula Szkody
• Host Institution: Instituto Nacional de Pesquisas Espaciais (INPE). Ministério da Ciência, Tecnologia e Inovações (Brasil). São José dos Campos , SP, Brazil
• Research place: University of Washington, United States
• Associated to the scholarship: 15/24393-7 - Modelling the intermediate polars using the CYCLOPS code, BP.DR

Abstract

Magnetic cataclysmic variables are compact binary systems in which mass transfer occurs from a low-mass star onto a magnetic white dwarf. In polars and intermediate polars subclass, the magnetic field of the white dwarf is strong enough to disrupt the inner accretion disk or even completely prevent disk formation. SW~Sextantis stars are a type of novalike cataclysmic variable, which show observational characteristics that indicate matter outside the orbital plane is distributed asymmetrically in azimuth. For example, most eclipsing SW Sex stars exhibit single-peaked emission lines rather than the double-peaked lines expected in high-inclination systems. Many scenarios have been proposed to explain the SW~Sex behavior, one of them is magnetic accretion. The general goal of this internship research project supervised by Dr. Paula Szkody is to study magnetic accretion in cataclysmic variables. As a first part of the project, we intend to search for signs of magnetic accretion in SW~Sex systems such as circular polarization and/or coherent photometric and/or polarimetric variability that can be associated with the white dwarf spin period. This part of the project has been started in my master's thesis using a sample of six objects-LS Peg, 1H 0204-023, SW Sex, V380 Oph, and V442 Oph-, for which we have recently obtained complementary observations. We also propose to conduct a search for magnetic cataclysmic variables candidates from sky surveys. These candidates should be validated by follow-up observations. The most interesting objects can be further studied by time-resolved observations and/or modelling.

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

OLIVEIRA, A. S.; RODRIGUES, C. V.; MARTINS, M.; PALHARES, M. S.; SILVA, K. M. G.; LIMA, I. J.; JABLONSKI, F. J.. Exploratory Spectroscopy of Magnetic Cataclysmic Variables Candidates and Other Variable Objects. II. ASTRONOMICAL JOURNAL, v. 159, n. 3, MAR 2020. (18/05420-1, 13/26258-4, 17/20309-7)

BELLONI, DIOGO; RODRIGUES, CLAUDIA V.; SCHREIBER, MATTHIAS R.; CASTRO, MANUEL; COSTA, JOAQUIM E. R.; HAYASHI, TAKAYUKI; LIMA, ISABEL J.; LUNA, GERARDO J. M.; MARTINS, MURILO; OLIVEIRA, ALEXANDRE S.; et al. reaking the Degeneracy in Magnetic Cataclysmic Variable X-Ray Spectral Modeling Using X-Ray Light Curve. ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES, v. 256, n. 2, OCT 2021. (17/20309-7, 13/26258-4, 17/13551-6, 18/05420-1, 15/25972-0, 17/14289-3)

LIMA, I. J.; RODRIGUES, C. V.; LOPES, C. E. FERREIRA; SZKODY, P.; JABLONSKI, F. J.; OLIVEIRA, A. S.; SILVA, K. M. G.; BELLONI, D.; PALHARES, M. S.; SHUGAROV, S.; et al. Search for Magnetic Accretion in SW Sextantis Systems. ASTRONOMICAL JOURNAL, v. 161, n. 5, MAY 2021. (17/14289-3, 17/20309-7, 13/26258-4, 18/05420-1)