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相关论文: The multiphase and magnetized neutral hydrogen see…

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We present deep polarimetric observations of the European Large Area ISO Survey-North 1 (ELAIS-N1) field using the Low Frequency Array (LOFAR) at 114.9-177.4 MHz. The ELAIS-N1 field is part of the LOFAR Two-metre Sky Survey deep fields data…

Filamentary structures in neutral hydrogen (HI) emission are well aligned with the interstellar magnetic field, so HI emission morphology can be used to construct templates that strongly correlate with measurements of polarized thermal dust…

星系天体物理 · 物理学 2024-09-04 George Halal , Susan E. Clark , Ari Cukierman , Dominic Beck , Chao-Lin Kuo

The precise measurement of the sky-averaged HI absorption signal between 50 and 200 MHz is the primary goal of global 21-cm cosmology. This measurement has the potential to unravel the underlying physics of cosmic structure formation and…

宇宙学与河外天体物理 · 物理学 2024-12-04 Emma Shen , Dominic Anstey , Marta Spinelli , Eloy de Lera Acedo , Anastasia Fialkov

Low-frequency polarisation observations of pulsars, facilitated by next-generation radio telescopes, provide powerful probes of astrophysical plasmas that span many orders of magnitude in magnetic field strength and scale: from pulsar…

高能天体物理现象 · 物理学 2018-08-22 C. Sobey , the LOFAR , MWA collaborations

We describe a Faraday-rotation structure in the Interstellar Medium detected through polarimetric imaging at 1420 MHz from the Canadian Galactic Plane Survey (CGPS). The structure, at l=91.8, b=-2.5, has an extent of ~2 degree, within which…

天体物理学 · 物理学 2009-11-07 B. Uyaniker , T. L. Landecker

Linear polarization of diffuse Galactic emission is a signature of magnetic fields in the interstellar medium of our Galaxy. Observations at high frequencies are less affected by Faraday depolarization than those at lower frequencies and…

星系天体物理 · 物理学 2015-05-27 L. Xiao , J. L. Han , W. Reich , X. H. Sun , R. Wielebinski , P. Reich , H. Shi , O. Lochner

We present a broadband spectropolarimetric survey of 563 discrete, mostly unresolved radio sources between 1.3 \& 2.0 GHz using data taken with the Australia Telescope Compact Array (ATCA). We have used rotation measure synthesis to…

星系天体物理 · 物理学 2015-12-16 C. S. Anderson , B. M. Gaensler , I. J. Feain , T. M. O. Franzen

Regular magnetic field structures can be derived from the Faraday rotation measures (RM) of polarized background sources observable at 1.4 GHz with the SKA. At lower frequencies ($<250$ MHz) polarimetry of radio sources with the Low…

宇宙学与河外天体物理 · 物理学 2009-04-20 Tigran G. Arshakian , Rainer Beck

Inter-galactic magnetic fields can imprint their structure on the morphology of blazar-induced gamma ray halos. We show that the halo morphology arises through the interplay of the source's jet and a two-dimensional surface dictated by the…

高能天体物理现象 · 物理学 2017-05-04 Francis Duplessis , Tanmay Vachaspati

We use numerical simulations of cosmic reionization and radiative processes related to the HI 21 cm emission line to produce synthetic radio maps as seen by next generation radio telescopes that will operate at low radio frequencies (e.g.…

天体物理学 · 物理学 2009-11-11 M. Valdes , B. Ciardi , A. Ferrara , M. Johnston-Hollitt , H. Rottgering

The low-temperature magnetic phase diagram of the multiferroic system FeTe$_2$O$_5$Br down to 300 mK and up to 9 T is presented. Short-range magnetic correlations within the crystal layers start to develop already at $\sim$50 K, i.e., far…

强关联电子 · 物理学 2015-05-19 M. Pregelj , A. Zorko , O. Zaharko , Z. Kutnjak , M. Jagodič , Z. Jagličić , H. Berger , M. de Souza , C. Balz , M. Lang , D. Arčon

The gases of the interstellar medium (ISM) possess orders of magnitude more mass than those of all the stars combined and are thus the prime component of the baryonic universe. With L-band surface sensitivity even better than the planned…

天体物理仪器与方法 · 物理学 2019-04-05 Carl Heiles , Di Li , Naomi McClure-Griffiths , Lei Qian , Shu Liu

We have studied the small scale distribution of atomic hydrogen (HI) using 21-cm absorption spectra against multiple-component background radio continuum sources from the 21-SPONGE survey and the Millennium Arecibo Absorption Line Survey.…

The interstellar medium (ISM) has a multiphase structure characterized by gas, dust and molecules. The gas can be found in different charge states: neutral, low-ionized (warm) and high-ionized (hot). It is possible to probe the multiphase…

高能天体物理现象 · 物理学 2013-02-19 C. Pinto , J. S. Kaastra , E. Costantini , F. Verbunt

Redshifted 21 cm radiation originating from the cosmological distribution of neutral hydrogen (HI) appears as a background radiation in low frequency radio observations. The angular and frequency domain fluctuations in this radiation carry…

天体物理学 · 物理学 2007-05-23 Somnath Bharadwaj , SK. Saiyad Ali

We explore the possibility of detecting HI 21cm absorption by the neutral intergalactic medium (IGM) toward very high redshift radio sources. The epoch considered is between the time when the first ionizing sources form and when the bulk of…

天体物理学 · 物理学 2016-08-30 C. Carilli , N. Y. Gnedin , F. Owen

We present observations of a new group of structures in the diffuse Galactic ISM: slender, linear HI features we dub "fibers" that extend for many degrees at high Galactic latitude. To characterize and measure the extent and strength of…

星系天体物理 · 物理学 2014-06-19 S E Clark , J E G Peek , M E Putman

Detection of the 21-cm signal coming from the epoch of reionization (EoR) is challenging especially because, even after removing the foregrounds, the residual Stokes $I$ maps contain leakage from polarized emission that can mimic the…

While emission and absorption lines of the 21 cm spin-flip transition of neutral Hydrogen are intrinsically unpolarized, a magnetic field creates left- and right-handed polarized components through the Zeeman effect. Here we consider the…

天体物理学 · 物理学 2016-08-30 Asantha Cooray , Steven Furlanetto

Starlight that becomes linearly polarized by magnetically aligned dust grains provides a viable diagnostic of the interstellar magnetic field (ISMF). A survey is underway to map the local ISMF using data collected at eight observatories in…