Search Results - "active galactic nuclei"

The suppression of star formation by powerful active galactic nuclei by Page, M., Symeonidis, M., Vieira, J., Altieri, B., Amblard, A., Arumugam, V., Aussel, H., Babbedge, T., Blain, A., Bock, J., Boselli, A., Buat, V., Castro-Rodríguez, N., Cava, A., Chanial, P., Clements, D., Conley, A., Conversi, L., Cooray, A., Dowell, C., Dubois, E., Dunlop, J., Dwek, E., Dye, S., Eales, S., Elbaz, D., Farrah, D., Fox, M., Franceschini, A., Gear, W., Glenn, J., Griffin, M., Halpern, M., Hatziminaoglou, E., Ibar, E., Isaak, K., Ivison, R., Lagache, G., Levenson, L., Lu, N., Madden, S., Maffei, B., Mainetti, G., Marchetti, L., Nguyen, H., O'Halloran, B., Oliver, S., Omont, A., Panuzzo, P., Papageorgiou, A., Pearson, C., Pérez-Fournon, I., Pohlen, M., Rawlings, J., Rigopoulou, D., Riguccini, L., Rizzo, D., Rodighiero, G., Roseboom, I., Rowan-Robinson, M., Sánchez Portal, M., Schulz, B., Scott, D., Seymour, Nick, Shupe, D., Smith, A., Stevens, J., Trichas, M., Tugwell, K., Vaccari, M., Valtchanov, I., Viero, M., Vigroux, L., Wang, L., Ward, R., Wright, G., Xu, C., Zemcov, M.

“…The old, red stars that constitute the bulges of galaxies, and the massive black holes at their centres, are the relics of a period in cosmic history when galaxies formed stars at remarkable rates and active galactic nuclei (AGN) shone brightly as a result of accretion onto black holes. …”
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The jet paths of radio active galactic nuclei and their cluster weather by Vardoulaki, E., Backöfer, V., Finoguenov, A., Vazza, F., Comparat, J., Gozaliasl, G., Whittam, I.H., Hale, C.L., Weaver, J.R., Koekemoer, A.M., Collier, Jordan, Frank, B., Heywood, I., Sekhar, S., Taylor, A.R., Pinjarkar, S., Hardcastle, M.J., Shimwell, T., Hoeft, M., White, S.V., An, F., Tabatabaei, F., Randriamanakoto, Z., Filipovic, M.D.

“…The radio data were obtained from the MeerKAT International GHz Tiered Extragalactic Explorations data release 1 (MIGHTEE-DR1) at 1.2-1.3 GHz, with angular resolutions of 8.9″ and 5″, and median noise levels of rmsmed ∼= 3.5 and 5.5 μJy/beam. Bent radio active galactic nuclei (AGN) were identified through visual inspection. …”
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Galaxy and Mass Assembly (GAMA): active galactic nuclei in pairs of galaxies by Gordon, Yjan A., Owers, Matt S., Pimbblet, Kevin A., Croom, Scott M., Alpaslan, Mehmet, Baldry, Ivan K., Brough, Sarah, Brown, Michael J.I., Cluver, Michelle E., Conselice, Christopher J., Davies, Luke J. M., Holwerda, Benne W., Hopkins, Andrew M., Gunawardhana, Madusha L.P., Loveday, Jonathan, Taylor, Edward N., Wang, Lingyu

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Time domain studies of Active Galactic Nuclei with the Square Kilometre Array by Bignall, Hayley, Croft, S., Hovatta, T., Koay, J., Lazio, J., Macquart, Jean-Pierre, Reynolds, Cormac

“…Variability of radio-emitting active galactic nuclei can be used to probe both intrinsic variations arising from shocks, flares, and other changes in emission from regions surrounding the central supermassive black hole, as well as extrinsic variations due to scattering by structures in our own Galaxy. …”
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Understanding high redshift Active Galactic Nuclei activity through infrared variability by Green, Karel

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HerMES: SPIRE emission from radio-selected active galactic nuclei by Seymour, Nick, Symeonidis, M., Page, M., Amblard, A., Arumugam, V., Aussel, H., Blain, A., Bock, J., Boselli, A., Buat, V., Castro-Rodríguez, N., Cava, A., Chanial, P., Clements, D., Conley, A., Conversi, L., Cooray, A., Dowell, C., Dwek, E., Eales, S., Elbaz, D., Franceschini, A., Glenn, J., Solares, E., Griffin, M., Hatziminaoglou, E., Ibar, E., Isaak, K., Ivison, R., Lagache, G., Levenson, L., Lu, N., Madden, S., Maffei, B., Mainetti, G., Marchetti, L., Nguyen, H., O'Halloran, B., Oliver, S., Omont, A., Panuzzo, P., Papageorgiou, A., Pearson, C., Pérez-Fournon, I., Pohlen, M., Rawlings, J., Rizzo, D., Roseboom, I., Rowan-Robinson, M., Schulz, B., Scott, D., Shupe, D., Smith, A., Stevens, J., Trichas, M., Tugwell, K., Vaccari, M., Valtchanov, I., Vigroux, L., Wang, L., Wright, G., Xu, C., Zemcov, M.

“…We estimate that radio-loud active galactic nuclei (AGN) in the high-redshift sample contribute 0.1–0.5 per cent to the total SFR density at that epoch. …”
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Why Do Compact Active Galactic Nuclei at High Redshift Scintillate Less? by Koay, Jun Yi, Macquart, Jean-Pierre, Rickett, B., Bignall, Hayley, Jauncey, D., Pursimo, T., Reynolds, Cormac, Lovell, J., Kedziora-Chudczer, L., Ojha, R.

“…The fraction of compact active galactic nuclei (AGNs) that exhibit interstellar scintillation (ISS) at radio wavelengths, as well as their scintillation amplitudes, have been found to decrease significantly for sources at redshifts z gsim 2. …”
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TANAMI: Tracking Active Galactic Nuclei with Austral Milliarcsecond Interferometry - II. Additional Sources by Müller, C., Kadler, M., Ojha, R., Schulz, R., Trüstedt, J., Edwards, P., Ros, E., Carpenter, B., Angioni, R., Blanchard, J., Böck, M., Burd, P., Dörr, M., Dutka, M., Eberl, T., Gulyaev, S., Hase, H., Horiuchi, S., Katz, U., Krauß, F., Lovell, J., Natusch, T., Nesci, R., Phillips, C., Plötz, C., Pursimo, T., Quick, J., Stevens, J., Thompson, D., Tingay, Steven, Tzioumis, A., Weston, S., Wilms, J., Zensus, J.

“…TANAMI is a multiwavelength program monitoring active galactic nuclei (AGN) south of -30deg declination including high-resolution Very Long Baseline Interferometry (VLBI) imaging, radio, optical/UV, X-ray and gamma-ray studies. …”
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HerMES: Disentangling active galactic nuclei and star formation in the radio source population by Rawlings, J., Page, M., Symeonidis, M., Bock, J., Cooray, A., Farrah, D., Guo, K., Hatziminaoglou, E., Ibar, E., Oliver, S., Roseboom, I., Scott, D., Seymour, Nick, Vaccari, M., Wardlow, J.

“…We separate the extragalactic radio source population above~50 µJy into active galactic nuclei (AGN) and star-forming sources. The primary method of our approach is to fit the infrared spectral energy distributions (SEDs), constructed using Spitzer/IRAC (Infrared Array Camera) and Multiband Imaging Photometer for Spitzer (MIPS) and Herschel/SPIRE photometry, of 380 radio sources in the Extended Chandra Deep Field-South. …”
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Characterizing the optical variability of bright blazars: Variability-based selection of fermi active galactic nuclei by Ruan, J., Anderson, S., MacLeod, C., Becker, A., Burnett, T., Davenport, J., Ivezic, Z., Kochanek, C., Plotkin, Richard, Sesar, B., Scott Stuart, J.

“…Despite the extreme stellar contamination at the shallow depth of the LINEAR survey, we are able to recover previously associated optical counterparts to Fermi active galactic nuclei with E = 88% and C = 88% in Fermi 95% confidence error ellipses having semimajor axis r < 8'. …”
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Detection of six rapidly scintillating active galactic nuclei and the diminished variability of J1819+3845 by Koay, J., Bignall, Hayley, Macquart, Jean-Pierre, Jauncey, D., Rickett, B., Lovell, J.

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Tracking the activity of supermassive black holes and the habitats of their hosts by Krishnan, Charutha

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Dual-frequency Observations of 140 Compact, Flat-spectrum Active Galactic Nuclei for Scintillation-induced Variability by Koay, J., Macquart, Jean-Pierre, Rickett, B.J., Bignall, Hayley, Lovell, J. E. J., Reynolds, Cormac, Jauncey, D. L., Pursimo, T., Kedziora-Chudczer, L., Ojha, R.

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Spectral properties and the effect on redshift cut-off of compact active galactic nuclei from the AT20G survey by Chhetri, R., Ekers, Ronald, Mahony, E., Jones, P., Massardi, M., Ricci, R., Sadler, E.

“…We use the recently published redshift data to study the effect of spectral curvature on the redshift cut-off of compact active galactic nuclei (AGNs). Using spectral indices at different frequencies, we correct for the redshift effect and also produce rest-frame frequency spectra for compact sources for redshifts up to z~ 5. …”
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Deep Spitzer observations of infrared-faint radio sources: High-redshift radio-loud active galactic nuclei? by Norris, R., Afonso, J., Cava, A., Farrah, D., Huynh, M., Ivison, R., Jarvis, M., Lacy, M., Mao, M., Maraston, C., Mauduit, J., Middelberg, E., Oliver, S., Seymour, Nick, Surace, J.

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Radio-loud narrow-line Seyfert 1 as a new class of gamma-ray active galactic nuclei by Abdo, A., Ackermann, M., Ajello, M., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Bechtol, K., Bellazzini, R., Berenji, B., Bloom, E., Bonamente, E., Borgland, A., Bregeon, J., Brez, A., Brigida, M., Bruel, P., Burnett, T., Caliandro, G., Cameron, R., Caraveo, P., Casandjian, J., Cecchi, C., Celik, O., Chekhtman, A., Cheung, C., Chiang, J., Ciprini, S., Claus, R., Cohen-Tanugi, J., Conrad, J., Cutini, S., Dermer, C., de Palma, F., Do Couto e Silva, E., Drell, P., Dubois, R., Dumora, D., Farnier, C., Favuzzi, C., Fegan, S., Focke, W., Foschini, L., Frailis, M., Fukazawa, Y., Fusco, P., Gargano, F., Gehrels, N., Germani, S., Giebels, B., Giglietto, N., Giordano, F., Giroletti, M., Glanzman, T., Godfrey, G., Grenier, I., Grove, J., Guillemot, L., Guiriec, S., Hayashida, M., Hays, E., Horan, D., Hughes, R., Johannesson, G., Johnson, A., Johnson, W., Kadler, M., Kamae, T., Katagiri, H., Kataoka, J., Kerr, M., Knödlseder, J., Kuss, M., Lande, J., Latronico, L., Longo, F., Loparco, F., Lott, B., Lovellette, M., Lubrano, P., Makeev, A., Mazziotta, M., McConville, W., McEnery, J., Meurer, C., Michelson, P., Mitthumsiri, W., Mizuno, T., Monte, C., Monzani, M., Morselli, A., Moskalenko, I., Murgia, S., Nolan, P., Norris, J., Nuss, E., Ohsugi, T., Omodei, N., Orlando, E., Ormes, J., Pelassa, V., Pepe, M., Persic, M., Pesce-Rollins, M., Piron, F., Porter, T., Raino, S., Rando, R., Razzano, M., Rochester, L., Rodriguez, A., Ryde, F., Sadrozinski, H., Sambruna, R., Sander, A., Saz Parkinson, P., Scargle, J., Sgro, C., Smith, P., Spandre, G., Spinelli, P., Strickman, M., Suson, D., Tagliaferri, G., Takahashi, H., Takahashi, T., Tanaka, T., Thayer, J., Thayer, J., Thompson, D., Tibaldo, L., Tibolla, Omar, Torres, D., Tosti, G., Tramacere, A., Uchiyama, Y., Usher, T., Vasileiou, V., Vilchez, N., Vitale, V., Waite, A., Wang, P., Winer, B., Wood, K., Ylinen, T., Ziegler, M., Ghisellini, G., Maraschi, L., Tavecchio, F.

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Galaxy clusters around radio-loud active galactic nuclei at 1.3 <z< 3.2 as seen by Spitzer by Wylezalek, D., Galametz, A., Stern, D., Vernet, J., De Breuck, C., Seymour, Nick, Brodwin, M., Eisenhardt, P., Gonzalez, A., Hatch, N., Jarvis, M., Rettura, A., Stanford, S., Stevens, J.

“…We report the first results from the Clusters Around Radio-Loud AGN program, a Cycle 7 and 8 Spitzer Space Telescope snapshot program to investigate the environments of a large sample of obscured and unobscured luminous radio-loud active galactic nuclei (AGNs) at 1.2 < z < 3.2. These data, obtained for 387 fields, reach 3.6 and 4.5 μm depths of [3.6]AB = 22.6 and [4.5]AB = 22.9 at the 95% completeness level, which is two to three times fainter than L* in this redshift range. …”
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A VLBA Search for Binary Black Holes in Active Galactic Nuclei with Double-peaked Optical Emission Line Spectra by Tingay, Steven, Wayth, Randall

“…We have examined a subset of 11 active galactic nuclei (AGNs) drawn from a sample of 87 objects that possess double-peaked optical emission line spectra, as put forward by Wang et al. and are detectable in the Faint Images of the Radio Sky at Twenty-centimeters (FIRST) survey at radio wavelengths. …”
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TANAMI: tracking active galactic nuclei with austral milliarcsecond interferometry . I. First-epoch 8.4 GHz images by Ojha, R., Kadler, M., Böck, M., Booth, R., Dutka, M., Tingay, Steven

“…A number of theoretical models vie to explain the γ-ray emission from active galactic nuclei (AGN). This was a key discovery of EGRET. …”
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MIGHTEE: deep 1.4 GHz source counts and the sky temperature contribution of star-forming galaxies and active galactic nuclei by Hale, C.L., Whittam, I.H., Jarvis, M.J., Best, P.N., Thomas, N.L., Heywood, I., Prescott, M., Adams, N., Afonso, J., An, F., Bowler, R.A.A., Collier, Jordan, Cook, R.H.W., Davé, R., Frank, B.S., Glowacki, M., Hatfield, P.W., Kolwa, S., Lovell, C.C., Maddox, N., Marchetti, L., Morabito, L.K., Murphy, E., Prandoni, I., Randriamanakoto, Z., Taylor, A.R.

“…We then use the wealth of ancillary data covering a subset of the COSMOS field to investigate the specific contributions from both active galactic nuclei (AGN) and star-forming galaxies (SFGs) to the source counts and sky background temperature. …”
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