Zobrazeno 1 - 10
of 293
pro vyhledávání: '"Callingham, J."'
Autor:
Callingham, J. R., Pope, B. J. S., Kavanagh, R. D., Bellotti, S., Daley-Yates, S., Damasso, M., Grießmeier, J. -M., Güdel, M., Günther, M., Kao, M. M., Klein, B., Mahadevan, S., Morin, J., Nichols, J. D., Osten, R. A., Pérez-Torres, M., Pineda, J. S., Rigney, J., Saur, J., Stefánsson, G., Turner, J. D., Vedantham, H., Vidotto, A. A., Villadsen, J., Zarka, P.
Radio detections of stellar systems provide a window onto stellar magnetic activity and the space weather conditions of extrasolar planets, information that is difficult to attain at other wavelengths. There have been recent advances observing aurora
Externí odkaz:
http://arxiv.org/abs/2409.15507
Autor:
de Ruiter, I., Rajwade, K. M., Bassa, C. G., Rowlinson, A., Wijers, R. A. M. J., Kilpatrick, C. D., Stefansson, G., Callingham, J. R., Hessels, J. W. T., Clarke, T. E., Peters, W., Wijnands, R. A. D., Shimwell, T. W., ter Veen, S., Morello, V., Zeimann, G. R., Mahadevan, S.
Recent observations have revealed rare, previously unknown flashes of cosmic radio waves lasting from milliseconds to minutes, and with periodicity of minutes to an hour [1-4]. These transient radio signals must originate from sources in the Milky Wa
Externí odkaz:
http://arxiv.org/abs/2408.11536
Publikováno v:
A&A 689, A264 (2024)
Recent sensitive wide-field radio surveys, such as the LOFAR Two Meter Sky Survey (LoTSS), the LOFAR LBA Sky Survey (LoLSS), and the Very Large Array Sky Survey (VLASS), enable the selection of statistically large samples of peaked-spectrum (PS) sour
Externí odkaz:
http://arxiv.org/abs/2406.13346
Autor:
Osinga, E., van Weeren, R. J., Brunetti, G., Adam, R., Rajpurohit, K., Botteon, A., Callingham, J. R., Cuciti, V., de Gasperin, F., Miley, G. K., Röttgering, H. J. A., Shimwell, T. W.
Publikováno v:
A&A 688, A175 (2024)
Merging galaxy clusters often host spectacular diffuse radio synchrotron sources. These sources can be explained by a non-thermal pool of relativistic electrons accelerated by shocks and turbulence in the intracluster medium. The origin of the pool a
Externí odkaz:
http://arxiv.org/abs/2405.09384
Autor:
Groeneveld, C., van Weeren, R. J., Osinga, E., Williams, W. L., Callingham, J. R., de Gasperin, F., Botteon, A., Shimwell, T., de Jong, J. M. G. H. J., Jansen, L. F., Miley, G. K., Brunetti, G., Brüggen, M., Röttgering, H. J. A.
Publikováno v:
Nature Astronomy 8 (2024) 786-795
The largely unexplored decameter radio band (10-30 MHz) provides a unique window for studying a range of astronomical topics, such as auroral emission from exoplanets, inefficient cosmic ray acceleration mechanisms, fossil radio plasma, and free-free
Externí odkaz:
http://arxiv.org/abs/2405.05311
Autor:
Fitzmaurice, Evan, Stefánsson, Gudmundur, Kavanagh, Robert D., Mahadevan, Suvrath, Cañas, Caleb I., Winn, Joshua N., Robertson, Paul, Ninan, Joe P., Albrecht, Simon, Callingham, J. R., Cochran, William D., Delamer, Megan, Kanodia, Shubham, Lin, Andrea S. J., Marcussen, Marcus L., Pope, Benjamin J. S., Ramsey, Lawrence W., Roy, Arpita, Vedantham, Harish, Wright, Jason T.
We characterize the LHS 1610 system, a nearby ($d=9.7$ pc) M5 dwarf hosting a brown dwarf in a $10.6$ day, eccentric ($e \sim 0.37$) orbit. A joint fit of the available Gaia two-body solution, discovery radial velocities (RVs) from TRES, and new RVs
Externí odkaz:
http://arxiv.org/abs/2310.07827
Autor:
Gloudemans, A. J., Saxena, A., Intema, H., Callingham, J. R., Duncan, K. J., Rottgering, H. J. A., Belladitta, S., Hardcastle, M. J., Harikane, Y., Spingola, C.
Publikováno v:
A&A 678, A128 (2023)
We present the low-frequency radio spectra of 9 high-redshift quasars at $5.6 \leq z \leq 6.6$ using the Giant Metre Radio Telescope band-3, -4, and -5 observations ($\sim$300-1200 MHz), archival Low Frequency Array (LOFAR; 144 MHz), and Very Large A
Externí odkaz:
http://arxiv.org/abs/2309.03936
Autor:
Gloudemans, A. J., Callingham, J. R., Duncan, K. J., Saxena, A., Harikane, Y., Hill, G. J., Zeimann, G. R., Rottgering, H. J. A., Hardcastle, M. J., Pineda, J. S., Shimwell, T. W., Smith, D. J. B., Wagenveld, J. D.
Publikováno v:
A&A 678, A161 (2023)
We present the serendipitous discovery of 8 distant ($>$ 50 pc) late M dwarfs with plausible associated radio emission at 144 MHz. The M dwarf nature of our sources has been confirmed with optical spectroscopy performed using HET/LRS2 and Subaru/FOCA
Externí odkaz:
http://arxiv.org/abs/2309.01741
Autor:
de Gasperin, F., Edler, H. W., Williams, W. L., Callingham, J. R., Asabere, B., Bruggen, M., Brunetti, G., Dijkema, T. J., Hardcastle, M. J., Iacobelli, M., Offringa, A., Norden, M. J., Rottgering, H. J. A., Shimwell, T., van Weeren, R. J., Tasse, C., Bomans, D. J., Bonafede, A., Botteon, A., Cassano, R., Chyzy, K. T., Cuciti, V., Emig, K. L., Kadler, M., Miley, G., Mingo, B., Oei, M. S. S. L., Prandoni, I., Schwarz, D. J., Zarka, P.
Publikováno v:
A&A 673, A165 (2023)
The Low Frequency Array (LOFAR) is the only existing radio interferometer able to observe at ultra-low frequencies (<100 MHz) with high resolution (<15") and high sensitivity (<1 mJy/beam). To exploit these capabilities, the LOFAR Surveys Key Science
Externí odkaz:
http://arxiv.org/abs/2301.12724
Autor:
Vedantham, H. K., Dupuy, Trent J., Evans, E. L., Sanghi, A., Callingham, J. R., Shimwell, T. W., Best, W. M. J., Liu, M. C., Zarka, P.
Publikováno v:
A&A 675, L6 (2023)
Brown dwarfs display Jupiter-like auroral phenomena such as magnetospheric H$\alpha$ emission and coherent radio emission. Coherent radio emission is a probe of magnetospheric acceleration mechanisms and provides a direct measurement of the magnetic
Externí odkaz:
http://arxiv.org/abs/2301.01003