Zobrazeno 1 - 10
of 119
pro vyhledávání: '"Gopakumar, Achamveedu"'
Autor:
Valtonen, Mauri J., Zola, Staszek, Gupta, Alok C., Kishore, Shubham, Gopakumar, Achamveedu, Jorstad, Svetlana G., Wiita, Paul J., Gu, Minfeng, Nilsson, Kari, Marscher, Alan P., Zhang, Zhongli, Hudec, Rene, Matsumoto, Katsura, Drozdz, Marek, Ogloza, Waldemar, Berdyugin, Andrei V., Reichart, Daniel E., Mugrauer, Markus, Dey, Lankeswar, Pursimo, Tapio, Lehto, Harry J., Ciprini, Stefano, Nakaoka, T., Uemura, M., Imazawa, Ryo, Zejmo, Michal, Kouprianov, Vladimir V., Davidson, Jr., James W., Sadun, Alberto, Strobl, Jan, Weaver, Z. R., Jelinek, Martin
We report the study of a huge optical intraday flare on November 12, 2021, at 2 am UT, in the blazar OJ287. In the binary black hole model it is associated with an impact of the secondary black hole on the accretion disk of the primary. Our multifreq
Externí odkaz:
http://arxiv.org/abs/2405.08627
Autor:
Agazie, Gabriella, Arzoumanian, Zaven, Baker, Paul T., Bécsy, Bence, Blecha, Laura, Blumer, Harsha, Brazier, Adam, Brook, Paul R., Burke-Spolaor, Sarah, Casey-Clyde, J. Andrew, Charisi, Maria, Chatterjee, Shami, Cheeseboro, Belinda D., Cohen, Tyler, Cordes, James M., Cornish, Neil J., Crawford, Fronefield, Cromartie, H. Thankful, DeCesar, Megan E., Demorest, Paul B., Dey, Lankeswar, Dolch, Timothy, Ellis, Justin A., Ferdman, Robert D., Ferrara, Elizabeth C., Fiore, William, Fonseca, Emmanuel, Freedman, Gabriel E., Garver-Daniels, Nate, Gentile, Peter A., Glaser, Joseph, Good, Deborah C., Gopakumar, Achamveedu, Gültekin, Kayhan, Hazboun, Jeffrey S., Jennings, Ross J., Johnson, Aaron D., Jones, Megan L., Kaiser, Andrew R., Kaplan, David L., Kelley, Luke Zoltan, Key, Joey S., Laal, Nima, Lam, Michael T., Lamb, William G., Lazio, T. Joseph W., Lewandowska, Natalia, Liu, Tingting, Lorimer, Duncan R., Luo, Jing, Lynch, Ryan S., Ma, Chung-Pei, Madison, Dustin R., McEwen, Alexander, McKee, James W., McLaughlin, Maura A., Meyers, Patrick M., Mingarelli, Chiara M. F., Mitridate, Andrea, Ng, Cherry, Nice, David J., Ocker, Stella Koch, Olum, Ken D., Pennucci, Timothy T., Pol, Nihan S., Radovan, Henri A., Ransom, Scott M., Ray, Paul S., Romano, Joseph D., Sardesai, Shashwat C., Schmitz, Kai, Siemens, Xavier, Simon, Joseph, Siwek, Magdalena S., Fiscella, Sophia V. Sosa, Spiewak, Renée, Stairs, Ingrid H., Stinebring, Daniel R., Stovall, Kevin, Susobhanan, Abhimanyu, Swiggum, Joseph K., Taylor, Stephen R., Turner, Jacob E., Unal, Caner, Vallisneri, Michele, Vigeland, Sarah J., Witt, Caitlin A., Young, Olivia
The radio galaxy 3C 66B has been hypothesized to host a supermassive black hole binary (SMBHB) at its center based on electromagnetic observations. Its apparent 1.05-year period and low redshift ($\sim0.02$) make it an interesting testbed to search f
Externí odkaz:
http://arxiv.org/abs/2309.17438
Autor:
Valtonen, Mauri J., Zola, Staszek, Gopakumar, Achamveedu, Lähteenmäki, Anne, Tornikoski, Merja, Dey, Lankeswar, Gupta, Alok C., Pursimo, Tapio, Knudstrup, Emil, Gomez, Jose L., Hudec, Rene, Jelínek, Martin, Štrobl, Jan, Berdyugin, Andrei V., Ciprini, Stefano, Reichart, Daniel E., Kouprianov, Vladimir V., Matsumoto, Katsura, Drozdz, Marek, Mugrauer, Markus, Sadun, Alberto, Zejmo, Michal, Sillanpää, Aimo, Lehto, Harry J., Nilsson, Kari, Imazawa, Ryo, Uemura, Makoto, Davidson Jr, James W.
The highly variable blazar OJ~287 is commonly discussed as an example of a binary black hole system. The 130 year long optical light curve is well explained by a model where the central body is a massive black hole of 18.35$\times$10$^9$ solar mass t
Externí odkaz:
http://arxiv.org/abs/2308.03017
Autor:
Valtonen, Mauri J., Dey, Lankeswar, Gopakumar, Achamveedu, Zola, Staszek, Lähteenmäki, Anne, Tornikoski, Merja, Gupta, Alok C., Pursimo, Tapio, Knudstrup, Emil, Gomez, Jose L., Hudec, Rene, Jelínek, Martin, Štrobl, Jan, Berdyugin, Andrei V., Ciprini, Stefano, Reichart, Daniel E., Kouprianov, Vladimir V., Matsumoto, Katsura, Drozdz, Marek, Mugrauer, Markus, Sadun, Alberto, Zejmo, Michal, Sillanpää, Aimo, Lehto, Harry J., Nilsson, Kari, Imazawa, Ryo, Uemura, Makoto
We present a summary of the results of the OJ 287 observational campaign, which was carried out during the 2021/2022 observational season. This season is special in the binary model because the major axis of the precessing binary happens to lie almos
Externí odkaz:
http://arxiv.org/abs/2308.01878
Gravitational Waves from Black-Hole Encounters: Prospects for Ground- and Galaxy-Based Observatories
Autor:
Dandapat, Subhajit, Ebersold, Michael, Susobhanan, Abhimanyu, Rana, Prerna, Gopakumar, Achamveedu, Tiwari, Shubhanshu, Haney, Maria, Lee, Hyung Mok, Kolhe, Neel
Close hyperbolic encounters of black holes (BHs) generate certain Burst With Memory (BWM) events in the frequency windows of the operational, planned, and proposed gravitational wave (GW) observatories. We present detailed explorations of the detecta
Externí odkaz:
http://arxiv.org/abs/2305.19318
Autor:
Ebersold, Michael, Tiwari, Shubhanshu, Smith, Leigh, Bae, Yeong-Bok, Kang, Gungwong, Williams, Daniel, Gopakumar, Achamveedu, Heng, Ik Siong, Haney, Maria
Publikováno v:
Phys. Rev. D 106, 104014 (2022)
Dense astrophysical environments like globular clusters and galactic nuclei can host hyperbolic encounters of black holes which can lead to gravitational-wave driven capture. There are several astrophysical models which predict a fraction of binary b
Externí odkaz:
http://arxiv.org/abs/2208.07762
Autor:
Joshi, Bhal Chandra, Gopakumar, Achamveedu, Pandian, Arul, Prabu, Thiagaraj, Dey, Lankeswar, Bagchi, Manjari, Desai, Shantanu, Tarafdar, Pratik, Rana, Prerna, Maan, Yogesh, Batra, Neelam Dhanda, Girgaonkar, Raghav, Agarwal, Nikita, Arumugam, Paramasivan, Banik, Sarmistha, Basu, Avishek, Bathula, Adarsh, Dandapat, Subhajit, Gupta, Yashwant, Hisano, Shinnosuke, Kato, Ryo, Kharbanda, Divyansh, Kikunaga, Tomonosuke, Kolhe, Neel, Krishnakumar, M. A., Manoharan, P. K., Marmat, Piyush, Naidu, Arun, Nobleson, K., Paladi, Avinash Kumar, Pathak, Dhruv, Singha, Jaikhomba, Srivastava, Aman, Surnis, Mayuresh, Susarla, Sai Chaitanya, Susobhanan, Abhimanyu, Takahashi, Keitaro
Decades long monitoring of millisecond pulsars, which exhibit highly stable rotational periods, in pulsar timing array experiments is on the threshold of discovering nanohertz stochastic gravitational wave background. This paper describes the Indian
Externí odkaz:
http://arxiv.org/abs/2207.06461
Autor:
Zhao, Guang-Yao, Gomez, Jose L., Fuentes, Antonio, Krichbaum, Thomas P., Traianou, E., Lico, Rocco, Cho, Ilje, Ros, Eduardo, Komossa, S., Akiyama, Kazunori, Asada, Keiichi, Blackburn, Lindy, Britzen, Silke, Bruni, Gabriele, Crew, Geoffrey, Dahale, Rohan, Dey, Lankeswar, Gold, Roman, Gopakumar, Achamveedu, Issaoun, Sara, Janssen, Michael, Jorstad, Svetlana G., Kim, Jae-Young, Koay, Jun Yi, Kovalev, Yuri Y., Koyama, Shoko, Lobanov, Andrei, Loinard, Laurent, Lu, Rusen, Markoff, Sera, Marscher, Alan P., Marti-Vidal, Ivan, Mizuno, Yosuke, Park, Jongho, Savolainen, Tuomas, Toscano, Teresa
Publikováno v:
ApJ 932 (2022) 72
We present the first very-long-baseline interferometric (VLBI) observations of the blazar OJ287 carried out jointly with the Global Millimeter VLBI Array (GMVA) and the phased Atacama Large Millimeter/submillimeter Array (ALMA) at 3.5 mm on April 2,
Externí odkaz:
http://arxiv.org/abs/2205.00554
Autor:
Gómez, Jose L., Traianou, Efthalia, Krichbaum, Thomas P., Lobanov, Andrei, Fuentes, Antonio, Lico, Rocco, Zhao, Guang-Yao, Bruni, Gabriele, Kovalev, Yuri Y., Lahteenmaki, Anne, Voitsik, Petr A., Lisakov, Mikhail M., Angelakis, Emmanouil, Bach, Uwe, Casadio, Carolina, Cho, Ilje, Dey, Lankeswar, Gopakumar, Achamveedu, Gurvits, Leonid, Jorstad, Svetlana G., Kovalev, Yuri A., Lister, Matthew L., Marscher, Alan P., Myserlis, Ioannis, Pushkarev, Alexander, Ros, Eduardo, Savolainen, Tuomas, Tornikoski, Merja, Valtonen, Mauri J., Zensus, Anton
Publikováno v:
ApJ 924 (2022) 122
We present the first polarimetric space VLBI observations of OJ 287, observed with RadioAstron at 22 GHz during a perigee session on 2014 April 4 and five near-in-time snapshots, together with contemporaneous ground VLBI observations at 15, 43, and 8
Externí odkaz:
http://arxiv.org/abs/2111.11200
Publikováno v:
Phys. Rev. D 105, 084018 (2022)
We compute the third post-Newtonian (3PN) accurate instantaneous contributions to the radiated gravitational wave (GW) energy and angular momentum arising from the hyperbolic passages of non-spinning compact objects. The present computations employ 3
Externí odkaz:
http://arxiv.org/abs/2111.00818