Results 61 to 70 of about 909 (203)

The Radio Parallax of the Crab Pulsar: A First VLBI Measurement Calibrated with Giant Pulses

The Astrophysical Journal, 2023
We use four observations with the European very long baseline interferometry (VLBI) network to measure the first precise radio parallax of the Crab Pulsar. We found two in-beam extragalactic sources just outside the Crab Nebula, with one bright enough to
Rebecca Lin, Marten H. van Kerkwijk, Franz Kirsten, Ue-Li Pen, Adam T. Deller   +4 more
doaj   +1 more source

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

The Celestial Reference Frame at K Band: Imaging. I. The First 28 Epochs

The Astronomical Journal, 2023
We present K -band (24 GHz) images of 731 compact extragalactic radio sources with submilliarcsecond resolution, based on radio interferometric observations made with the Very Long Baseline Array of 10 telescopes during 29 day long sessions spanning from
Aletha de Witt, Christopher S. Jacobs, David Gordon, K-band Celestial Reference Frame Collaboration, Michael Bietenholz, Marisa Nickola, Alessandra Bertarini   +6 more
doaj   +1 more source

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

HAWC J0630+186 Could Not Be Powered by PSR J0630+19

The Astrophysical Journal
3HWC J0630+186 is one of the very-high-energy gamma-ray sources listed in the third High-Altitude Water Cherenkov catalog; however, its origin remains unidentified.
Bojun Wang, Xiaohong Cui, Jiguang Lu, Heng Xu, Renxin Xu   +4 more
doaj   +1 more source

Constraints on the Persistent Radio Source Associated with FRB 20190520B Using the European VLBI Network

The Astrophysical Journal Letters, 2023
We present very long baseline interferometry (VLBI) observations of a continuum radio source potentially associated with the fast radio burst source FRB 20190520B.
Shivani Bhandari, Benito Marcote, Navin Sridhar, Tarraneh Eftekhari, Jason W. T. Hessels, Danté M. Hewitt, Franz Kirsten, Omar S. Ould-Boukattine, Zsolt Paragi, Mark P. Snelders   +9 more
doaj   +1 more source

A Radio Counterpart to a Jupiter-mass Binary Object in Orion

The Astrophysical Journal Letters
Using James Webb Space Telescope near-infrared data of the inner Orion Nebula, Pearson & McCaughrean detected 40 Jupiter-mass binary objects (JuMBOs).
Luis F. Rodríguez, Laurent Loinard, Luis A. Zapata   +2 more
doaj   +1 more source

JWST imaging of the closest globular clusters—I. Possible infrared excess among white dwarfs in NGC 6397

Astronomische Nachrichten, Volume 345, Issue 6-7, July-August 2024.
Abstract We present James Webb Space Telescope observations of the globular cluster NGC 6397 and use them to extend to infrared wavelengths the characterization of the cluster's entire white dwarf (WD) cooling sequence (CS). The data allows us to probe fundamental astrophysical WD properties and to search for evidence in their colors for (or against ...
L. R. Bedin, D. Nardiello, M. Salaris, M. Libralato, P. Bergeron, A. J. Burgasser, D. Apai, M. Griggio, M. Scalco, J. Anderson, R. Gerasimov, A. Bellini   +11 more
wiley   +1 more source

On discussion of the consequences of revolution in astrometry at the start of XXI century

, 2018
The purpose of the paper is to draw attention to the problems emerged in optical astrometry. It had to be developed by specialists in a new-born branch of radio physics named radio astrometry.
S.A. Tolchelnikova
core   +1 more source

A Study of Real-time Detection Methods for Solar Radio Burst Identification

The Astrophysical Journal Supplement Series
Solar flares, coronal mass ejections, and other solar radio burst phenomena release substantial amounts of solar radiation energy, resulting in adverse space weather conditions and posing significant hazards in space. Spectrum analysis conducted manually
YongLin Yu, ChengLong Qiao, Shuo Xu, QinZheng Li, YanRui Su, HongQiang Song, FaBao Yan   +6 more
doaj   +1 more source