Zobrazeno 1 - 10
of 111
pro vyhledávání: '"Cellone, Sergio A."'
Autor:
Dhiman, Vinit, Gupta, Alok C., Bachev, Rumen, Wiita, Paul J., Cellone, Sergio A., Strigachev, A., Gaur, Haritma, Darriba, A., Bisen, D. P., Locatelli, G., Mammana, L. A., Semkov, E.
We report the first extensive optical flux and spectral variability study of the TeV blazar TXS 0506+056 on intra-night to long-term timescales using BVRI data collected over 220 nights between January 21, 2017 to April 9, 2022 using 8 optical ground
Externí odkaz:
http://arxiv.org/abs/2311.02352
Autor:
Roy, Abhradeep, Gupta, Alok C., Chitnis, Varsha R., Cellone, Sergio A., Raiteri, Claudia M., Romero, Gustavo E., Wiita, Paul J., Chatterjee, Anshu, Combi, Jorge A., Liao, Mai, Sarkar, Arkadipta, Villata, Massimo
We present a long-term and intraday variability study on optical multiwaveband ($U\!BV\!RI$) data from the blazar AO 0235+164 collected by various telescopes for $\sim$44 years (1975--2019). The blazar was found to be significantly variable over the
Externí odkaz:
http://arxiv.org/abs/2301.01944
Autor:
Roy, Abhradeep, Chitnis, Varsha R., Gupta, Alok C., Wiita, Paul J., Romero, Gustavo E., Cellone, Sergio A., Chatterjee, Anshu, Combi, Jorge A., Raiteri, Claudia M., Sarkar, Arkadipta, Villata, Massimo
We present a long term optical $R$ band light curve analysis of the gravitationally lensed blazar AO 0235+164 in the time span 1982 - 2019. Several methods of analysis lead to the result that there is a periodicity of ~8.13 years present in these dat
Externí odkaz:
http://arxiv.org/abs/2205.03586
Autor:
Prince, Raj, Agarwal, Aditi, Gupta, Nayantara, Majumdar, Pratik, Czerny, Bożena, Cellone, Sergio A., Andruchow, I.
Publikováno v:
A&A 654, A38 (2021)
Context. The blazar OJ 287 has been proposed as a binary black hole system based on its periodic optical outburst. Among blazars with parsec scale jets, the black hole binary systems are very rare and hence this source is very interesting to study. A
Externí odkaz:
http://arxiv.org/abs/2105.04028
Autor:
Agarwal, A., Mihov, B., Andruchow, I., Cellone, Sergio A., Anupama, G. C., Agrawal, V., Zola, S., Slavcheva-Mihova, L., Ozdonmez, Aykut, Ege, Ergun, Raj, Ashish, Mammana, Luis, Zibecchi, L., Fernández-Lajús, E.
Publikováno v:
A&A 645, A137 (2021)
Context. The TeV BL Lac object PG 1553+113 is one of the primary candidates for a binary supermassive black hole system. Aims. We study the flux and spectral variability of PG 1553+113 on intra-night to long-term timescales using (i) BVRI data collec
Externí odkaz:
http://arxiv.org/abs/2011.04074
Autor:
Agarwal, Aditi, Cellone, Sergio A., Andruchow, Ileana, Mammana, Luis, Singh, Mridweeka, Anupama, G. C., Mihov, B., Raj, Ashish, Slavcheva-Mihova, L., Özdönmez, Aykut, Ege, Ergün
We have monitored the flat spectrum radio quasar, 3C 279, in the optical $B$, $V$, $R$ and $I$ passbands from 2018 February to 2018 July for 24 nights, with a total of 716 frames, to study flux, colour and spectral variability on diverse timescales.
Externí odkaz:
http://arxiv.org/abs/1908.01465
Autor:
Forte, Juan C., Cellone, Sergio A., De Rossi, María E., Escudero, Carlos G., Faifer, Favio R., Geisler, Douglas, González, Nélida M., Scalia, María C., Sesto, Leandro A., Castelli, Analía V. Smith, Vega, E. Irene
The presence of systematic modulations in the colour distributions in composite samples of globular clusters associated with galaxies in the Virgo and Fornax clusters has been reported in a previous work. In this paper we focus on the 27 brightest ga
Externí odkaz:
http://arxiv.org/abs/1810.04784
Autor:
González, Nélida M., Castelli, Analía V. Smith, Faifer, Favio R., Escudero, Carlos G., Cellone, Sergio A.
Publikováno v:
A&A 620, A166 (2018)
To enlarge the sample of known low-surface brightness (LSB) galaxies and to try to provide clues about their nature, we report the detection of eight of this type of objects ($\mu_{{eff}, g'} \simeq 27$ mag arcsec$^{-2}$) towards the group of galaxie
Externí odkaz:
http://arxiv.org/abs/1810.00710
We present a statistical isophotal analysis of 138 early-type galaxies in the Antlia cluster, located at a distance of ${\sim} 35$ Mpc. The observational material consists of CCD images of four $36$ arcmin ${\times} 36$ arcmin fields obtained with th
Externí odkaz:
http://arxiv.org/abs/1803.03678
Autor:
Torres-Zafra, Juanita, Cellone, Sergio A., Buzzoni, Alberto, Andruchow, Ileana, Portilla, José G.
The BL Lac object 3C66A is one of the most luminous extragalactic sources at TeV $\gamma$-rays (VHE, i.e. $E >100$ GeV). Since TeV $\gamma$-ray radiation is absorbed by the extragalactic background light (EBL), it is crucial to know the redshift of t
Externí odkaz:
http://arxiv.org/abs/1710.04309