Zobrazeno 1 - 10
of 53
pro vyhledávání: '"Emilia Järvelä"'
Autor:
Luigi Foschini, Benedetta Dalla Barba, Merja Tornikoski, Heinz Andernach, Paola Marziani, Alan P. Marscher, Svetlana G. Jorstad, Emilia Järvelä, Sonia Antón, Elena Dalla Bontà
Publikováno v:
Universe, Vol 10, Iss 4, p 156 (2024)
We present the results of a comparison between different methods to estimate the power of relativistic jets from active galactic nuclei (AGN). We selected a sample of 32 objects (21 flat-spectrum radio quasars, 7 BL Lacertae objects, 2 misaligned AGN
Externí odkaz:
https://doaj.org/article/7b712abdb41f4738b77788e76dff659c
Autor:
Sina Chen, Preeti Kharb, Silpa Sasikumar, Sumana Nandi, Marco Berton, Emilia Järvelä, Ari Laor, Ehud Behar, Luigi Foschini, Amelia Vietri, Minfeng Gu, Giovanni La Mura, Luca Crepaldi, Minhua Zhou
Publikováno v:
The Astrophysical Journal, Vol 963, Iss 1, p 32 (2024)
We present new 1.5–8.5 GHz Very Long Baseline Array (VLBA) observations and 0.32–1.26 GHz Giant Meterwave Radio Telescope (GMRT) observations of J0354−1340, which is the only known radio-quiet (RQ) or radio-intermediate (RI) narrow-line Seyfert
Externí odkaz:
https://doaj.org/article/8f84c7ce88df40579ac8829bbb60bcb7
Publikováno v:
Frontiers in Astronomy and Space Sciences, Vol 8 (2021)
Narrow-line Seyfert 1 (NLS1) galaxies are active galactic nuclei (AGN) believed to be in the early stages of their evolution. A fraction of them have been found to host relativistic jets. Due to the lack of large-scale diffuse radio emission they are
Externí odkaz:
https://doaj.org/article/43562a519673480c9ad38ef8cb1f6283
Autor:
Luigi Foschini, Matthew L. Lister, Heinz Andernach, Stefano Ciroi, Paola Marziani, Sonia Antón, Marco Berton, Elena Dalla Bontà, Emilia Järvelä, Maria J. M. Marchã, Patrizia Romano, Merja Tornikoski, Stefano Vercellone, Amelia Vietri
Publikováno v:
Universe, Vol 8, Iss 11, p 587 (2022)
We considered the fourth catalog of gamma-ray point sources produced by the Fermi Large Area Telescope (LAT) and selected only jetted active galactic nuclei (AGN) or sources with no specific classification, but with a low-frequency counterpart. Our f
Externí odkaz:
https://doaj.org/article/2ccdb86d97d14331bc9bfd07b415854b
Autor:
Luigi Foschini, Matthew L. Lister, Sonia Antón, Marco Berton, Stefano Ciroi, Maria J. M. Marchã, Merja Tornikoski, Emilia Järvelä, Patrizia Romano, Stefano Vercellone, Elena Dalla Bontà
Publikováno v:
Universe, Vol 7, Iss 10, p 372 (2021)
We are compiling a new list of gamma-ray jetted active galactic nuclei (AGN), starting from the fourth catalog of point sources of the Fermi Large Area Telescope (LAT). Our aim is to prepare a list of jetted AGN with known redshifts and classificatio
Externí odkaz:
https://doaj.org/article/93e5bb9ad62a47268be5d567ffd42bfb
Autor:
Marco Berton, Emilia Järvelä
Publikováno v:
Universe, Vol 7, Iss 6, p 188 (2021)
It is well known that active galactic nuclei (AGN) show various forms of interaction with their host galaxy, in a number of phenomena generally called AGN feedback. In particular, the relativistic plasma jets launched by a fraction of AGN can strongl
Externí odkaz:
https://doaj.org/article/7dd61316a9d546b2ba83cfdfd5d66400
Publikováno v:
Frontiers in Astronomy and Space Sciences, Vol 4 (2017)
The large-scale environment is believed to affect the evolution and intrinsic properties of galaxies. It offers a new perspective on narrow-line Seyfert 1 galaxies (NLS1) which have not been extensively studied in this context before. We study a larg
Externí odkaz:
https://doaj.org/article/cc52cf6e381440449b405ef991bec1b1
Autor:
Sina Chen, Jamie B Stevens, Philip G Edwards, Ari Laor, Minfeng Gu, Marco Berton, Emilia Järvelä, Preeti Kharb, Ehud Behar, Renzhi Su
Publikováno v:
Monthly Notices of the Royal Astronomical Society. 512:471-489
We present radio spectral analyses for a sample of 29 radio-quiet (RQ) and three radio-loud (RL) narrow-line Seyfert 1 galaxies (NLS1s) detected with the Australia Telescope Compact Array at both 5.5 and 9.0 GHz. The sample is characterized by Lbol/L
Autor:
Sebastian Rabien, Stefano Ciroi, S. Komossa, Marco Berton, Emilia Järvelä, Iskren Y. Georgiev, Sonia Antón, L. Busoni, Smita Mathur, Alessandro Caccianiga, Timothy S. Hamilton, Wolfgang Gässler
Publikováno v:
Monthly Notices of the Royal Astronomical Society. 504:5188-5198
The gamma-ray emitting galaxy SBS 0846+513 has been classified as a Narrow-Line Seyfert 1 from its spectroscopy, and on that basis it was thought likely to have a small central black hole hosted in a spiral galaxy. But very few of the gamma-ray Narro
Autor:
Andrea Tarchi, Marco Berton, A. Vietri, Emilia Järvelä, G. La Mura, Sina Chen, L. Crepaldi, Alessandro Caccianiga, M. E. Jarvis, F. Di Mille, Enrico Congiu, Preeti Kharb
Publikováno v:
MNRAS
In this paper, we present the analysis of new radio and optical observations of the narrow-line Seyfert 1 galaxy Mrk 783. 1.6 GHz observations performed with the e-MERLIN interferometer confirm the presence of the diffuse emission previously observed