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Related papers: Modelling the ArH$^+$ emission from the Crab Nebul…

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We report ~ 600 days of BATSE earth-occultation observations of the total gamma-ray (30 keV to 1.7 MeV) emission from the Crab nebula, between 1991 May 24 (TJD 8400) and 1994 October 2 (TJD 9627). Lightcurves from 35-100, 100-200, 200-300,…

Astrophysics · Physics 2009-11-10 J. C. Ling , Wm. A. Wheaton

The HI environment of the Crab Nebula is investigated using 2.75' and 9' resolution data from (respectively) the DRAO Synthesis, and Effelsberg 100 m, radio telescopes. No clear evidence for an interaction between the Crab and the…

Astrophysics · Physics 2009-10-31 B. J. Wallace , T. L. Landecker , P. M. W. Kalberla , A. R. Taylor

We report the detection of emission in the v=1-0 P(1) (3.51629 micron) and P(2) (3.60776 micron) rovibrational lines of the helium hydride cation (HeH+) from the planetary nebula NGC 7027. These detections were obtained with the iSHELL…

Astrophysics of Galaxies · Physics 2020-05-13 David A. Neufeld , Miwa Goto , T. R. Geballe , Rolf Güsten , Karl M. Menten , Helmut Wiesemeyer

The discovery of rapid synchrotron gamma-ray flares above 100 MeV from the Crab Nebula has attracted new interest in alternative particle acceleration mechanisms in pulsar wind nebulae. Diffuse shock-acceleration fails to explain the flares…

High Energy Astrophysical Phenomena · Physics 2015-06-17 Benoit Cerutti , Gregory R. Werner , Dmitri A. Uzdensky , Mitchell C. Begelman

The Crab nebula is a prominent pulsar wind nebula (PWN) detected in multiband observations ranging from radio to very high-energy (VHE) $\gamma$-rays. Recently, $\gamma$-rays with energies above $1 \mathrm{PeV}$ had been detected by the…

High Energy Astrophysical Phenomena · Physics 2022-01-05 Lu Wen , Ke-Yao Wu , Huan Yu , Jun Fang

The kinematic and morphological properties of a string of [Ar III] bright knots in the Crab Nebula are examined using 1994 - 1999 HST WFPC-2 images of the remnant. We find that five southern [Ar III] bright knots exhibit ordinary radial…

Astrophysics · Physics 2009-11-07 Emily L. Schaller , Robert A. Fesen

We report about very high energy (VHE) gamma-ray observations of the Crab Nebula with the MAGIC telescope. The gamma-ray flux from the nebula was measured between 60 GeV and 9 TeV. The energy spectrum can be described with a curved power…

Astrophysics · Physics 2009-06-23 MAGIC Collaboration , J. Albert

Infrared emission features at 3.3, 6.2, 7.7, 8.6, and 11.2 $\mu$m, attributed to polycyclic aromatic hydrocarbons, show variations in relative intensity, shape, and peak position. These variations depend on the physical conditions of the…

Astrophysics of Galaxies · Physics 2021-11-24 C. Knight , E. Peeters , M. Wolfire , D. J. Stock

We show that the mysterious, rapidly variable emission at ~400 MeV observed from the Crab Nebula by the AGILE and Fermi experiments could be the result of a sudden drop in the mass-loading of the pulsar wind. The current required to…

High Energy Astrophysical Phenomena · Physics 2017-11-29 John G. Kirk , Gwenael Giacinti

Far-infrared Herschel PACS imaging and spectroscopic observations of the nebula around the luminous blue variable (LBV) star AG Car have been obtained along with optical imaging in the Halpha+[NII] filter. In the infrared light, the nebula…

Solar and Stellar Astrophysics · Physics 2015-06-17 C. Vamvatira-Nakou , D. Hutsemekers , P. Royer , N. L. J. Cox , Y. Naze , G. Rauw , C. Waelkens , M. A. T. Groenewegen

The Crab Nebula, also known as Tau A, is a polarized astronomical source at millimeter wavelengths. It has been used as a stable light source for polarization angle calibration in millimeter-wave astronomy. However, it is known that its…

Neutron stars generate powerful winds of relativistic particles that form bright synchrotron nebulae around them. Polarimetry provides a unique insight into the geometry and magnetic configuration of the wind, but high-energy measurements…

Astrophysics · Physics 2009-11-13 M. Forot , Philippe Laurent , I A. Grenier , C. Gouiffes , F. Lebrun

We have analyzed 16 years of observations dedicated to the Crab (pulsar + nebula) with the INTEGRAL SPI instrument to investigate its polarization properties. We find that the source presents a substantially polarized emission (PF = 24%) in…

High Energy Astrophysical Phenomena · Physics 2019-09-25 E. Jourdain , J. P. Roques

We present the first phase-resolved study of the X-ray spectral properties of the Crab Pulsar that covers all pulse phases. The superb angular resolution of the Chandra X-ray Observatory enables distinguishing the pulsar from the…

Routine observations of the Crab Nebula for a total of about 250 hrs, performed with the HEGRA stereoscopic system of 5 imaging atmospheric Cerenkov telescopes in the standard operational mode, have proven the energy threshold of the system…

Astrophysics · Physics 2009-11-07 F. Lucarelli , A. Konopelko , F. Aharonian , W. Hofmann , A. Kohnle , H. Lampeitl , V. Fonseca

We present spectral analysis of the Crab Nebula obtained with the {\it Chandra} X-ray observatory. The X-ray spectrum is characterized by a power-law whose index varies across the nebula. The variation can be discussed in terms of the…

Astrophysics · Physics 2009-11-10 K. Mori , D. N. Burrows , J. J. Hester , G. G. Pavlov , S. Shibata , H. Tsunemi

Understanding how molecules and dust might have formed within a rapidly expanding young supernova remnant is important because of the obvious application to vigorous supernova activity at very high redshift. In previous papers, we found…

Astrophysics of Galaxies · Physics 2015-06-12 C. T. Richardson , J. A. Baldwin , G. J. Ferland , E. D. Loh , C. A. Kuehn , A. C. Fabian , Philippe Salomé

Having no any explanations the radiation of high-frequency components of the pulsar in the Crab Nebula can be a manifestation of instability in the nonlinear reflection from the neutron star surface. Reflected radiation it is the radiation…

High Energy Astrophysical Phenomena · Physics 2017-02-07 Victor M. Kontorovich

It has been argued by Jacobson, Liberati and Mattingly that synchrotron radiation from the Crab Nebula imposes a stringent constraint on any modification of the dispersion relations of the electron that might be induced by quantum gravity.…

Astrophysics · Physics 2009-09-11 J. Ellis , N. E. Mavromatos , A. S. Sakharov

We have constructed MOCASSIN photoionization plus dust radiative transfer models for the Crab Nebula core-collapse supernova (CCSN) remnant, using either smooth or clumped mass distributions, in order to determine the chemical composition…

Astrophysics of Galaxies · Physics 2015-06-23 P. J. Owen , M. J. Barlow