Results 61 to 70 of about 11,697 (215)

A strong radio brightening at the jet base of M87 during the elevated very-high-energy gamma-ray state in 2012

, 2014
We report our intensive radio monitoring observations of the jet in M87 with the VLBI Exploration of Radio Astrometry (VERA) and the European VLBI Network (EVN) from February 2011 to October 2012, together with contemporaneous high-energy gamma-ray light
Akiyama, K., Beilicke, M., Casadio, C., Cesarini, A., Cheung, C. C., D'Ammando, F., Doi, A., Giovannini, G., Giroletti, M., Gomez, J. L., Gurwell, M. A., Hada, K., Honma, M., Kino, M., Koyama, S., Krawczynski, H., Nagai, H., Nakahara, S., Niinuma, K., Orienti, M., Sawada-Satoh, S.   +20 more
core   +2 more sources

Isolated Neutron Stars as Science Validation for XMM2ATHENA: Ensuring Robust Data for Future X‐Ray Astronomy

Astronomische Nachrichten, Volume 346, Issue 3-4, March-May 2025.
ABSTRACT The discovery of radio‐quiet, x‐ray thermally emitting isolated neutron stars (XINSs) in the ROSAT All‐Sky Survey revealed a previously overlooked component of the neutron star population. Advancements in x‐ray instrumentation and the availability of deep, wide‐area optical surveys now enable us to explore XINSs at fainter x‐ray fluxes and ...
Adriana Mancini Pires, Christian Motch, Axel Schwope, Iris Traulsen, Jean Ballet, Sudip Chakraborty, David Homan, Jan Kurpas, Ada Nebot Gomez‐Moràn, François‐Xavier Pineau, Hugo Tranin, Natalie Webb   +11 more
wiley   +1 more source

Probing the Turbulent Corona and Heliosphere Using Radio Spectral Imaging Observation during the Solar Conjunction of the Crab Nebula

The Astrophysical Journal
Measuring plasma parameters in the upper solar corona and inner heliosphere is challenging because of the region’s weakly emissive nature and inaccessibility for most in situ observations.
Peijin Zhang, Surajit Mondal, Bin Chen, Sijie Yu, Dale Gary, Marin M. Anderson, Judd D. Bowman, Ruby Byrne, Morgan Catha, Xingyao Chen, Sherry Chhabra, Larry D’Addario, Ivey Davis, Jayce Dowell, Katherine Elder, Gregg Hallinan, Charlie Harnach, Greg Hellbourg, Jack Hickish, Rick Hobbs, David Hodge, Mark Hodges, Yuping Huang, Andrea Isella, Daniel C. Jacobs, Ghislain Kemby, John T. Klinefelter, Matthew Kolopanis, Nikita Kosogorov, James Lamb, Casey J. Law, Nivedita Mahesh, Brian O’Donnell, Kathryn Plant, Corey Posner, Travis Powell, Vinand Prayag, Andres Rizo, Andrew Romero-Wolf, Jun Shi, Greg Taylor, Jordan Trim, Mike Virgin, Akshatha Vydula, Sandy Weinreb, David Woody   +45 more
doaj   +1 more source

Astrometry of Galactic Star-Forming Region G48.61+0.02 with VERA

, 2011
We performed the astrometry of H2O masers in the Galactic star-forming region G48.61+0.02 with the VLBI Exploration of Radio Astrometry (VERA). We derived a trigonometric parallax of 199+/-7 micro as, which corresponds to a distance of 5.03+/-0.19 kpc ...
Handa, Toshihiro, Honma, Mareki, Kawaguchi, Noriyuki, Kobayashi, Hideyuki, Nagayama, Takumi, Nakagawa, Akiharu, Omodaka, Toshihiro, Ueno, Yuji   +7 more
core   +1 more source

Microarcsecond VLBI pulsar astrometry with PSRPI I. Two binary millisecond pulsars with white dwarf companions [PDF]

, 2016
Model-independent distance constraints to binary millisecond pulsars (MSPs) are of great value to both the timing observations of the radio pulsars, and multiwavelength observations of their companion stars.
Brisken, W. F., Chatterjee, S., Cordes, J. M., Deller, A. T., Goss, W. M., Janssen, G. H., Kaplan, D. L., Lazio, T. J. W., Lyne, A., Petrov, L., Stappers, B. W., Vigeland, S. J.   +11 more
core   +2 more sources

Multi‐Instrument and SAMI3‐TIDAS Data Assimilation Analysis of Three‐Dimensional Ionospheric Electron Density Variations During the April 2024 Total Solar Eclipse

Journal of Geophysical Research: Space Physics, Volume 129, Issue 9, September 2024.
Abstract This paper conducts a multi‐instrument and data assimilation analysis of the three‐dimensional ionospheric electron density responses to the total solar eclipse on 08 April 2024. The altitude‐resolved electron density variations over the continental US and adjacent regions are analyzed using the Millstone Hill incoherent scatter radar data ...
Ercha Aa, Joseph Huba, Shun‐Rong Zhang, Anthea J. Coster, Philip J. Erickson, Larisa P. Goncharenko, Juha Vierinen, William Rideout   +7 more
wiley   +1 more source

Partial Alignment of Astrometric Position Excursions of International Celestial Reference Frame Quasars with Radio Jet Structures

The Astrophysical Journal Letters
Published analyses of very long baseline interferometry data for the sources included in the third International Celestial Reference Frame catalog have revealed object-specific, excess astrometric variability and quasi-coherent trajectories as functions ...
Valeri V. Makarov, Phil Cigan, David Gordon, Megan C. Johnson, Christopher DiLullo, Sébastien Lambert   +5 more
doaj   +1 more source

Precision Astrometry with the Very Long Baseline Array: Parallaxes and Proper Motions for 14 Pulsars

, 2009
Astrometry can bring powerful constraints to bear on a variety of scientific questions about neutron stars, including their origins, astrophysics, evolution, and environments.
A. G. Lyne, Arras, Arzoumanian, Beasley, Blazek, Bridle, Briggs, Brisken, Brisken, Brisken, Brisken, Chatterjee, Chatterjee, Chatterjee, Cordes, Cordes, Cornwell, Dame, De Luca, de Zeeuw, Deller, E. B. Fomalont, Faucher-Giguère, Fey, Fomalont, Fomalont, Fomalont, Haffner, Harrison, Helfand, Hoogerwerf, J. M. Cordes, Janka, Kaplan, Kaplan, Kaplan, Kaplan, Kramer, Lai, M. Kramer, Ma, Migliazzo, Ng, Ng, Petrov, Romney, S. Chatterjee, S. E. Thorsett, Socrates, Splaver, Standish, T. J. W. Lazio, Thorsett, Toscano, Verbiest, Vlemmings, W. F. Brisken, W. H. T. Vlemmings, W. M. Goss, Walker, Walker, Walter, Winkler, Zeiger   +63 more
core   +1 more source

VLBA images of the precessing jet of LSI+61303

, 2012
Context: In 2004, changes in the radio morphology of the Be/X-ray binary system LSI+61303 suggested that it is a precessing microquasar. In 2006, a set of VLBA observations performed throughout the entire orbit of the system were not used to study its ...
Bosch-Ramon, Casares, Dubus, E. Ros, Fender, Frail, Gregory, Hada, Kaufman Bernadó, L. Zimmermann, Larwood, Lestrade, Lestrade, M. Massi, Markoff, Marscher, Marti, Martí-Vidal, Massi, Massi, Massi, Massi, Massi, Massi, Massi, Paredes, Peracaula, Pradel, Rickett, Romero, Russell, Taylor   +31 more
core   +1 more source

The location of an active nucleus and a shadow of a tidal tail in the ULIRG Mrk 273 [PDF]

, 2011
Analysis of data from the Chandra X-ray Observatory for the double nucleus ULIRG Mrk 273 reveals an absorbed hard X-ray source coincident with the southwest nucleus, implying that this unresolved, near-infrared source is where an active nucleus resides ...
Armus, L., Evans, A. S., Howell, J. H., Iwasawa, K., Komossa, S., Mazzarella, J. M., Petric, A., Sanders, D. B., Surace, J. A., Teng, S. H., U, V., Veilleux, S.   +11 more
core   +2 more sources