Results 91 to 100 of about 21,097,663 (248)

Position and Proper Motion of Sagittarius A* in the ICRF3 Frame from VLBI Absolute Astrometry [PDF]

, 2023
David Gordon, Aletha de Witt, C. S. Jacobs   +2 more
openalex   +1 more source

Detection of Intrinsic Source Structure at ∼3 Schwarzschild Radii with Millimeter-VLBI Observations of SAGITTARIUS A* [PDF]

, 2018
We report results from very long baseline interferometric (VLBI) observations of the supermassive black hole in the Galactic center, Sgr A*, at 1.3 mm (230 GHz). The observations were performed in 2013 March using six VLBI stations in Hawaii, California,
R. Lu, R. Lu, T. Krichbaum, A. Roy, V. Fish, S. Doeleman, S. Doeleman, Michael D. Johnson, K. Akiyama, K. Akiyama, D. Psaltis, W. Alef, K. Asada, C. Beaudoin, A. Bertarini, A. Bertarini, L. Blackburn, R. Blundell, G. Bower, C. Brinkerink, A. Broderick, A. Broderick, R. Cappallo, G. Crew, J. Dexter, M. Dexter, H. Falcke, H. Falcke, H. Falcke, R. Freund, P. Friberg, C. Greer, M. Gurwell, P. Ho, M. Honma, M. Inoue, Junhan Kim, J. Lamb, M. Lindqvist, D. MacMahon, D. Marrone, I. Mart'i-Vidal, K. Menten, J. Moran, N. Nagar, R. Plambeck, R. Primiani, A. Rogers, E. Ros, E. Ros, H. Rottmann, J. SooHoo, J. Spilker, J. Spilker, J. Stone, P. Strittmatter, R. Tilanus, R. Tilanus, M. Titus, L. Vertatschitsch, J. Wagner, J. Wagner, J. Weintroub, M. Wright, K. Young, J. Zensus, L. Ziurys   +66 more
semanticscholar   +1 more source

Inside the Stagnation Radius of the Nearest Billion-solar-mass Black Hole

The Astrophysical Journal
We used the NSF Jansky Very Large Array at a frequency ν  = 22 GHz to study the nearest billion-solar-mass black hole (BH), in the early-type galaxy NGC 3115 at a distance of 9.7 Mpc.
J. M. Wrobel, D. W. Pesce, K. E. Nyland
doaj   +1 more source

Polarization in Sagittarius A*

, 2000
Invited Article, 5 pages, 1 ...
openaire   +2 more sources

PERSISTENT ASYMMETRIC STRUCTURE OF SAGITTARIUS A* ON EVENT HORIZON SCALES [PDF]

, 2016
The Galactic Center black hole Sagittarius A* (Sgr A*) is a prime observing target for the Event Horizon Telescope (EHT), which can resolve the 1.3 mm emission from this source on angular scales comparable to that of the general relativistic shadow ...
V. Fish, Michael D. Johnson, S. Doeleman, A. Broderick, D. Psaltis, R. Lu, K. Akiyama, W. Alef, J. Algaba, K. Asada, C. Beaudoin, A. Bertarini, L. Blackburn, R. Blundell, G. Bower, C. Brinkerink, R. Cappallo, A. Chael, R. Chamberlin, Chi-kwan Chan, G. Crew, J. Dexter, M. Dexter, S. Dzib, H. Falcke, R. Freund, P. Friberg, C. Greer, M. Gurwell, P. Ho, M. Honma, M. Inoue, T. Johannsen, Junhan Kim, T. Krichbaum, J. Lamb, J. Le'on-Tavares, A. Loeb, L. Loinard, D. MacMahon, D. Marrone, J. Moran, M. Mo'scibrodzka, G. Ortiz-Le'on, T. Oyama, F. Ozel, R. Plambeck, N. Pradel, R. Primiani, A. Rogers, K. Rosenfeld, H. Rottmann, A. Roy, C. Ruszczyk, D. Smythe, J. SooHoo, J. Spilker, J. Stone, P. Strittmatter, R. Tilanus, M. Titus, L. Vertatschitsch, J. Wagner, J. Wardle, J. Weintroub, D. Woody, M. Wright, P. Yamaguchi, A. Young, K. Young, J. Zensus, L. Ziurys   +71 more
semanticscholar   +1 more source

Neutron-Capture Element Abundances in Planetary Nebulae

Galaxies, 2020
Nebular spectroscopy is a valuable tool for assessing the production of heavy elements by slow neutron(n)-capture nucleosynthesis (the s-process). Several transitions of n-capture elements have been identified in planetary nebulae (PNe) in the last few ...
N. C. Sterling
doaj   +1 more source

Simultaneous Monitoring of X-Ray and Radio Variability in Sagittarius A* [PDF]

, 2017
Monitoring of Sagittarius A* from X-ray to radio wavelengths has revealed structured variability—including X-ray flares—but it is challenging to establish correlations between them.
D. Capellupo, D. Haggard, Nicolas Choux, F. Baganoff, G. Bower, B. Cotton, N. Degenaar, J. Dexter, H. Falcke, P. C. Fragile, C. Heinke, C. Law, S. Markoff, J. Neilsen, G. Ponti, N. Rea, F. Yusef-Zadeh   +16 more
semanticscholar   +1 more source

An Inward-moving and Asymmetric Velocity Wave Detected in LAMOST-Gaia

The Astrophysical Journal Letters
The phase space, as coded by kinematic parameters and chemical abundances, is crucial for understanding the formation of the Galactic disk. Using red giant stars from the Galactic thin disk with [Fe/H] > − 0.8 and low- α ratios identified in LAMOST-Gaia,
Yuqin Chen, Gang Zhao, Wenbo Wu, Zixi Guo, Haopeng Zhang, Zhuohan Li   +5 more
doaj   +1 more source

Galactic substructure traced by RR Lyraes in SDSS Stripe 82

EPJ Web of Conferences, 2012
Using a sample of 407 RR Lyrae stars extracted from SDSS Stripe 82, we study the degree of substructure in the Galactic halo. We identify overdensities associated with the known substructures of the Hercules-Aquila Cloud and the Sagittarius Stream, and ...
Watkins L.
doaj   +1 more source

The Core Mass Function across Galactic Environments. IV. The Galactic Center

The Astrophysical Journal
The origin of the stellar initial mass function (IMF) and how it may vary with galactic environment is a matter of debate. Certain star formation theories involve a close connection between the IMF and the core mass function (CMF), so it is important to ...
Alva V. I. Kinman, Maya A. Petkova, Jonathan C. Tan, Giuliana Cosentino, Yu Cheng   +4 more
doaj   +1 more source