Zobrazeno 1 - 10
of 35
pro vyhledávání: '"Oliveira, Alexandre S."'
Autor:
Lima, Isabel J., Luna, G. Juan M., Mukai, Koji, Oliveira, Alexandre S., Sokoloski, Jennifer L., Walter, Fred, Palivanas, Natalia, Nuñez, Natalia E., Souza, Rafael R., Araujo, Rosana A. N.
White dwarf symbiotic binaries are detected in X-rays with luminosities in the range of 10$^{30}$ to 10$^{34}$ lumcgs. Their X-ray emission arises either from the accretion disk boundary layer, from a region where the winds from both components colli
Externí odkaz:
http://arxiv.org/abs/2405.01508
Autor:
Lima, Isabel J., Mattiuci, Ana C., Luna, G. Juan M., Oliveira, Alexandre S., Rodrigues, Claudia V., Palivanas, Natalia, Nunez, Natalia E.
We present an analysis of publicly available X-ray and optical observations of TYC 7275-1968-1, a contact binary, red nova progenitor candidate. The long optical time series of ASAS-SN, SuperWASP, CRTS, GAIA, ASAS-3, and TESS enabled us to improve it
Externí odkaz:
http://arxiv.org/abs/2310.19712
Autor:
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., Parsons, Steven G., Silva, Karleyne M. G., Stecchini, Paulo E., Stuchi, Teresa J., Zorotovic, Monica
We present an analysis of mock X-ray spectra and light curves of magnetic cataclysmic variables using an upgraded version of the 3D CYCLOPS code. This 3D representation of the accretion flow allows us to properly model total and partial occultation o
Externí odkaz:
http://arxiv.org/abs/2107.10861
Autor:
Oliveira, Alexandre S., Rodrigues, Claudia V., Martins, Murilo, Palhares, Matheus S., Silva, Karleyne M. G., Lima, Isabel J., Jablonski, Francisco J.
Publikováno v:
2020, The Astronomical Journal, Volume 159, Issue 3, id.114
This is the second paper of a series presenting our search for magnetic Cataclysmic Variables (mCVs) among candidates selected mostly from the Catalina Real-Time Transient Survey (CRTS). We present the identification spectra, obtained at the SOAR Tel
Externí odkaz:
http://arxiv.org/abs/2001.10582
Autor:
Oliveira, Alexandre S., Rodrigues, Claudia V., Palhares, Matheus S., Diaz, Marcos P., Belloni, Diogo, Silva, Karleyne M. G.
Post-shock regions (PSR) of polar cataclysmic variables produce most of their luminosity and give rise to high circular polarization in optical wavelengths and strong variability on the white dwarf rotation period, which are distinctive features of t
Externí odkaz:
http://arxiv.org/abs/1909.00874
An exoplanet transiting in front of the disk of its parent star may hide a dark starspot causing a detectable change in the light curve, that allows to infer physical characteristics of the spot such as size and intensity. We have analysed the Kepler
Externí odkaz:
http://arxiv.org/abs/1703.00883
We report the analysis of 22 B-band light curves of the dwarf nova V4140 Sgr obtained with SOI/SOAR during two nights along the decline of a superoutburst in 2006 Sep 12-24 and in quiescence over 50 days following the superoutburst. Three-dimensional
Externí odkaz:
http://arxiv.org/abs/1609.03453
Publikováno v:
2010IAUS..262..390M
NGC 404, at a distance of 3.4 Mpc, is the nearest S0 galaxy. This galaxy harbors a LINER; however, since the spectrum does not show a broad H{\alpha} emission, it is not certain that this LINER is a low luminosity AGN and its nature is still an open
Externí odkaz:
http://arxiv.org/abs/1006.4893
Publikováno v:
2010IAUS..267..123M
In this work, we present an analysis of a data cube obtained with the instrument IFU/GMOS Gemini North telescope centered on the nuclear region of the LINER galaxy NGC 4579. This galaxy is known to have a type 1 AGN (see Eracleous et al. 2002 for a r
Externí odkaz:
http://arxiv.org/abs/1006.4896
Autor:
Oliveira, Alexandre S., Steiner, J. E.
Publikováno v:
Mon.Not.Roy.Astron.Soc. 351 (2004) 685
We confirm the orbital period of WX Cen (WR 48c) determined by Diaz & Steiner (1995) and refined its value to P = 0.416 961 5 d. The light curve of this object has an amplitude of 0.32 magnitudes and has a V-shaped narrow minimum, similar to the ones
Externí odkaz:
http://arxiv.org/abs/astro-ph/0403281