Balmer-dominated shocks in Tycho’s SNR: omnipresence of CRs

AbstractWe present wide-field, spatially and highly resolved spectroscopic observations of Balmer filaments in the northeastern rim of Tycho’s supernova remnant in order to investigate the signal of cosmic-ray (CR) acceleration. The spectra of Balmer-dominated shocks (BDSs) have characteristic narrow (FWHM ~ 10 km s−1) and broad (FWHM ~ 1000 km s−1) Hα components. CRs affect the Hα-line parameters: heating the cold neutrals in the interstellar medium results in broadening of the narrow Hα-line width beyond 20 km s−1, but also in reduction of the broad Hα-line width due to energy being removed from the protons in the post-shock region. For the first time we show that the width of the narrow Hα line, much larger than 20 km s−1, is not a resolution or geometric effect nor a spurious result of a neglected intermediate (FWHM ~ 100 km s−1) component resulting from hydrogen atoms undergoing charge exchange with warm protons in the broad-neutral precursor. Moreover, we show that a narrow line width ≫ 20 km s−1extends across the entire NE rim, implying CR acceleration is ubiquitous, and making it possible to relate its strength to locally varying shock conditions. Finally, we find several locations along the rim, where spectra are significantly better explained (based on Bayesian evidence) by inclusion of the intermediate component, with a width of 180 km s−1on average.

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UVscope and its application aboard the ASTRI-Horn telescope

Experimental Astronomy ◽

10.1007/s10686-021-09728-6 ◽

2021 ◽

Author(s):

Maria Concetta Maccarone ◽

Giovanni La Rosa ◽

Osvaldo Catalano ◽

Salvo Giarrusso ◽

Alberto Segreto ◽

...

Keyword(s):

Gamma Ray ◽

Single Photon ◽

Photon Counting ◽

Light Flux ◽

Cosmic Ray ◽

High Energy ◽

Wide Field ◽

High Energy Astrophysics ◽

Single Photon Counting ◽

Photon Counting Mode

AbstractUVscope is an instrument, based on a multi-pixel photon detector, developed to support experimental activities for high-energy astrophysics and cosmic ray research. The instrument, working in single photon counting mode, is designed to directly measure light flux in the wavelengths range 300-650 nm. The instrument can be used in a wide field of applications where the knowledge of the nocturnal environmental luminosity is required. Currently, one UVscope instrument is allocated onto the external structure of the ASTRI-Horn Cherenkov telescope devoted to the gamma-ray astronomy at very high energies. Being co-aligned with the ASTRI-Horn camera axis, UVscope can measure the diffuse emission of the night sky background simultaneously with the ASTRI-Horn camera, without any interference with the main telescope data taking procedures. UVscope is properly calibrated and it is used as an independent reference instrument for test and diagnostic of the novel ASTRI-Horn telescope.

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Measurement of the cosmic ray proton spectrum from 40 GeV to 100 TeV with the DAMPE satellite

Science Advances ◽

10.1126/sciadv.aax3793 ◽

2019 ◽

Vol 5 (9) ◽

pp. eaax3793 ◽

Cited By ~ 16

Author(s):

◽

Q. An ◽

R. Asfandiyarov ◽

P. Azzarello ◽

P. Bernardini ◽

...

Keyword(s):

Cosmic Rays ◽

Cosmic Radiation ◽

Precise Measurement ◽

Milky Way ◽

Spectral Feature ◽

Dark Matter Particle ◽

Cosmic Ray ◽

Galactic Cosmic Rays ◽

Proton Spectrum ◽

First Time

The precise measurement of the spectrum of protons, the most abundant component of the cosmic radiation, is necessary to understand the source and acceleration of cosmic rays in the Milky Way. This work reports the measurement of the cosmic ray proton fluxes with kinetic energies from 40 GeV to 100 TeV, with 2 1/2 years of data recorded by the DArk Matter Particle Explorer (DAMPE). This is the first time that an experiment directly measures the cosmic ray protons up to ~100 TeV with high statistics. The measured spectrum confirms the spectral hardening at ~300 GeV found by previous experiments and reveals a softening at ~13.6 TeV, with the spectral index changing from ~2.60 to ~2.85. Our result suggests the existence of a new spectral feature of cosmic rays at energies lower than the so-called knee and sheds new light on the origin of Galactic cosmic rays.

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Resolved Stellar Populations of the interacting galaxies of the M81 group

Proceedings of the International Astronomical Union ◽

10.1017/s1743921316011108 ◽

2016 ◽

Vol 11 (S321) ◽

pp. 22-24

Author(s):

Sakurako Okamoto ◽

Nobuo Arimoto ◽

Annette M.N. Ferguson ◽

Edouard J. Bernard ◽

Mike J. Irwin ◽

...

Keyword(s):

Main Sequence ◽

Field Survey ◽

State Of The Art ◽

Young Stars ◽

Interacting Galaxies ◽

Wide Field ◽

Red Giant ◽

Tidal Streams ◽

Stellar Associations ◽

First Time

AbstractWe present the results from the state-of-the-art wide-field survey of the M81 galaxy group that we are conducting with Hyper Suprime-Cam on Subaru Telescope. Our photometry reaches about 2 mag below the tip of the red giant branch (RGB) and reveals the spatial distribution of both old and young stars over an area of 5°2around the M81. The young main-sequence (MS) stars closely follow the HI distribution and can be found in a stellar stream between M81 and NGC 3077 and in numerous outlying stellar associations. Our survey also reveals for the first time the very extended (>2 × R25) halos of RGB stars around M81, M82, and NGC 3077, as well as faint tidal streams that link these systems. The gravitational interactions between M81, M82 and NGC 3077 galaxies induced star formation in tidally stripped gas, and also significantly perturbed the older stellar components leading to disturbed halo morphologies.

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Narrow line-width resonant cavity enhanced photodetectors operating at 1.55μm

Optics Communications ◽

10.1016/j.optcom.2007.11.081 ◽

2008 ◽

Vol 281 (6) ◽

pp. 1582-1587 ◽

Cited By ~ 5

Author(s):

R.W. Mao ◽

C.S. Tsai ◽

J.Z. Yu ◽

Q.M. Wang

Keyword(s):

Line Width ◽

Resonant Cavity ◽

Narrow Line ◽

Narrow Line Width

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A tunable narrow-line-width multi-wavelength Er-doped fiber laser based on a high birefringence fiber ring mirror and an auto-tracking filter

Optics Communications ◽

10.1016/j.optcom.2007.09.009 ◽

2008 ◽

Vol 281 (1) ◽

pp. 90-93 ◽

Cited By ~ 16

Author(s):

Xiu-jie Jia ◽

Yan-ge Liu ◽

Li-bin Si ◽

Zhan-cheng Guo ◽

Sheng-gui Fu ◽

...

Keyword(s):

Fiber Laser ◽

Line Width ◽

Narrow Line ◽

Fiber Ring ◽

High Birefringence ◽

Narrow Line Width ◽

Multi Wavelength ◽

Tracking Filter ◽

Er Doped

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A Stable Narrow Line-Width Dual-Wavelength Fiber Laser Based on Nonlinear Polarization Rotation with a High Finesse Ring Filter

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.130-134.1876 ◽

2011 ◽

Vol 130-134 ◽

pp. 1876-1879

Author(s):

Xiu Feng Yang ◽

Lei Peng ◽

Zheng Rong Tong ◽

Ye Cao ◽

Feng Juan Dong

Keyword(s):

Fiber Laser ◽

Line Width ◽

Extinction Ratio ◽

Dual Wavelength ◽

Narrow Line ◽

Polarization Rotation ◽

Nonlinear Polarization ◽

Narrow Line Width ◽

Nonlinear Polarization Rotation ◽

High Finesse

A stable narrow line-width dual-wavelength fiber laser based on nonlinear polarization rotation with a high finesse ring filter is proposed and demonstrated. A polarization-dependent-isolator (PDI) and a section of polarization maintaining fiber (PMF) form an equivalent birefringent filter. Moreover, a ring filter can produce high finesse due to the weak gain generated by the EDF. As a result, two stable wavelengths are generated which both have about 18dB extinction ratio, 16dB side mode suppression ratio (SMSR) and 0.16nm 3dB line-width. Plus, less than 2 pm of the wavelengths shift and smaller than 0.4 dB of the optical power fluctuation when the system is operating in room environment for a period of 40 minutes indicate that the ultra narrow line-width fiber laser is very stable.

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