Please use this identifier to cite or link to this item:
http://hdl.handle.net/20.500.12386/34605
Title: | The Orion-Taurus ridge: a synchrotron radio loop at the edge of the Orion-Eridanus superbubble | Authors: | BRACCO, Andrea PADOVANI, Marco Juan D. Soler |
Issue Date: | 2023 | Journal: | ASTRONOMY & ASTROPHYSICS | Number: | 677 | First Page: | L11 | Abstract: | Large-scale synchrotron loops are recognized as the main source of diffuse radio-continuum emission in the Galaxy at intermediate and high Galactic latitudes. Their origin, however, remains rather unexplained. Using a combination of multi-frequency data in the radio band of total and polarized intensities, for the first time in this letter, we associate one arc -- hereafter, the Orion-Taurus ridge -- with the wall of the most prominent stellar-feedback blown shell in the Solar neighborhood, namely the Orion-Eridanus superbubble. We traced the Orion-Taurus ridge using 3D maps of interstellar dust extinction and column-density maps of molecular gas, $N_{\rm H_2}$. We found the Orion-Taurus ridge at a distance of 400\,pc, with a plane-of-the-sky extent of $180$\,pc. Its median $N_{\rm H_2}$ value is $(1.4^{+2.6}_{-0.6})\times 10^{21}$ cm$^{-2}$. Thanks to the broadband observations below 100 MHz of the Long Wavelength Array, we also computed the low-frequency spectral-index map of synchrotron emissivity, $\beta$, in the Orion-Taurus ridge. We found a flat distribution of $\beta$ with a median value of $-2.24^{+0.03}_{-0.02}$ that we interpreted in terms of depletion of low-energy ($<$ GeV) cosmic-ray electrons in recent supernova remnants ($10^5$ - $10^6$ yrs). Our results are consistent with plane-of-the-sky magnetic-field strengths in the Orion-Taurus ridge larger than a few tens of $\mu$G ($> 30 - 40 \,\mu$G). We report the first detection of diffuse synchrotron emission from cold-neutral, partly molecular, gas in the surroundings of the Orion-Eridanus superbubble. This observation opens a new perspective to study the multiphase and magnetized interstellar medium with the advent of future high-sensitivity radio facilities, such as the C-Band All-Sky Survey and the Square Kilometre Array. | URI: | http://hdl.handle.net/20.500.12386/34605 | URL: | https://www.aanda.org/articles/aa/full_html/2023/09/aa47283-23/aa47283-23.html | ISSN: | 0004-6361 | DOI: | 10.1051/0004-6361/202347283 | Fulltext: | open |
Appears in Collections: | 1.01 Articoli in rivista |
Files in This Item:
File | Description | Size | Format | |
---|---|---|---|---|
aa47283-23-1.pdf | PDF editoriale | 1.79 MB | Adobe PDF | View/Open |
2308.16663-min.pdf | postprint | 752.37 kB | Adobe PDF | View/Open |
Page view(s)
13
checked on Sep 1, 2024
Download(s)
11
checked on Sep 1, 2024
Google ScholarTM
Check
Altmetric
Altmetric
Items in DSpace are published in Open Access, unless otherwise indicated.