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相关论文: MASIV:The Microarcsecond Scintillation-Induced Var…

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Stars exhibit a bewildering variety of rapidly variable behaviors ranging from explosive magnetic flares to stochastically changing accretion to periodic pulsations or rotation. The principal Rubin Observatory Legacy Survey of Space and…

太阳与恒星天体物理 · 物理学 2023-08-02 Eric D. Feigelson , Federica B. Bianco , Rosaria Bonito

MASSIV (Mass Assembly Survey with SINFONI in VVDS) is a sample of 84 distant star-forming galaxies observed with the SINFONI Integral Field Unit (IFU) on the VLT. These galaxies are selected inside a redshift range of 0.8 < z < 1.9, i.e.…

High-amplitude variability in Young Stellar Objects (YSOs) is usually associated with episodic accretion events. It has not been observed so far in massive YSOs. Here, the high-amplitude variable star sample of ContrerasPe\~{n}a et…

太阳与恒星天体物理 · 物理学 2016-12-14 M. S. N. Kumar , C. Contreras-Pena , P. W. Lucas , M. A. Thompson

We report on an effort to extract and monitor interstellar scintillation parameters in regular timing observations collected for the NANOGrav pulsar timing array. Scattering delays are measured by creating dynamic spectra for each pulsar…

We report the discovery of VVV-WIT-04, a near-infrared variable source towards the Galactic disk located ~0.2 arcsec apart from the position of the radio source PMN J1515-5559. The object was found serendipitously in the near-IR data of the…

We show that surface waves along interstellar current sheets closely aligned with the line of sight lead to pulsar scintillation properties consistent with those observed. This mechanism naturally produces the length and density scales of…

星系天体物理 · 物理学 2015-06-15 Ue-Li Pen , Yuri Levin

An in-depth analysis of variability has been carried out on the 2 GHz and 8 GHz light curves from the impressive database of the US Navy's extragalactic source monitoring program at the Green Bank Interferometer (GBI), complemented by UMRAO…

高能天体物理现象 · 物理学 2025-02-05 Nicola Marchili , Gunther Witzel , Margo F. Aller

We present flux-ratio curves of the fold and cusp (i.e. close multiple) images of six JVAS/CLASS gravitational lens systems. The data were obtained over a period of 8.5 months in 2001 with the Multi-Element Radio-Linked Interferometer…

We examine the long-term evolution of the intra-hour variable quasar, J1819+3845, whose variations have been attributed to interstellar scintillation by extremely local turbulent plasma, located only 1-3pc from Earth. The variations in this…

星系天体物理 · 物理学 2015-06-22 A. G. de Bruyn , J. -P. Macquart

The VVV microlensing search has recently surveyed the region of the Galactic plane at b=0 within -10.00 < l < 10.44 deg. in the near-infrared (IR), discovering hundreds of microlensing events. In this paper we explore the microlensing…

太阳与恒星天体物理 · 物理学 2020-10-14 Maria Gabriela Navarro , Dante Minniti , Rodrigo Contreras Ramos

We search for microlensing events in the highly reddened areas surrounding the Galactic center using the near-IR observations with the VISTA Variables in the V\'ia L\'actea Survey (VVV). We report the discovery of 182 new microlensing…

太阳与恒星天体物理 · 物理学 2017-12-22 María Gabriela Navarro , Dante Minniti , Rodrigo Contreras Ramos

It was recently suggested by Boldyrev & Gwinn that the characteristics of radio scintillations from distant pulsars are best understood if the interstellar electron-density fluctuations that cause the time broadening of the radio pulses…

天体物理学 · 物理学 2010-11-11 Stanislav Boldyrev , Arieh Konigl

We consider interstellar scintillations as a cause of intermittency in radio signals from extraterrestrial intelligence (ETI). We demonstrate that scintillations are very likely to allow initial detections of narrowband signals from distant…

天体物理学 · 物理学 2009-10-30 James M. Cordes , T. Joseph W. Lazio , Carl Sagan

The observed interstellar scintillation pattern of an intra-day variable radio source is influenced by its source structure. If the velocity of the interstellar medium responsible for the scattering is comparable to the earth's, the vector…

天体物理学 · 物理学 2009-11-07 J-P Macquart , D. L. Jauncey

The interstellar scintillation observed in radio pulsars arises from interference between electromagnetic waves scattered by electron density fluctuations in the turbulent interstellar plasma, providing a critical tool for probing the…

We derive the distribution of interferometric visibility for a source exhibiting strong diffractive scintillation, with particular attention to spectral resolution at or near the Nyquist limit. We also account for arbitrary temporal…

天体物理仪器与方法 · 物理学 2015-06-15 Michael D. Johnson , Carl R. Gwinn

Radio monitoring of the gravitational lens system B0218+357 reveals it to be a highly variable source with variations on timescales of a few days correlated in both images. This shows that the variability is intrinsic to the background…

天体物理学 · 物理学 2007-05-23 A. D. Biggs , I. W. A. Browne , P. N. Wilkinson

To determine the location of the intra-day variable (IDV) emission region within the jet of the BL Lac object S5 0716+714, a multi-epoch VSOP polarization experiment was performed in Autumn 2000. To detect, image, and monitor the short term…

天体物理学 · 物理学 2009-11-11 U. Bach , T. P. Krichbaum , A. Kraus , A. Witzel , J. A. Zensus

We present results of a pilot observational wide-field VLBI campaign on probing scattering properties of the partly ionized interstellar medium towards the Galactic plane sky region between $28^\circ<l<36^\circ$ and $|b|<1^\circ$. This…