English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

We study the interaction of cosmic rays (CRs) with the diffuse circumgalacticgas of Milky Way (MW) galaxy that results in hadronic $\gamma-$ray emission andradio synchrotron emission. We aim to constrain the CR population in ourcircumgalactic medium (CGM) with the help of observed isotropic $\gamma$-raybackground (IGRB), its anisotropy and radio continuum. We modify differentmodels of CGM gas in hydrostatic equilibrium discussed in literature byincluding a cosmic ray population, parametrized by $\eta \equiv P_{\rmCR}/P_{\rm th}$. For the simplest isothermal model, while the IGRB intensityallows $\eta \lesssim 3$, the anisotropy resulting from the Solar system'soff-center position in MW rules out all values of $\eta$. For the precipitationmodel, in which the cooling of the CGM gas is regulated with an optimum ratioof cooling time to free-fall time,while the observed IGRB intensity allows$\eta \lesssim 230$, the observed anisotropy allows only very large values of$\eta$, of order $\gtrsim 100$. The radio continuum limits $\eta \lesssim 400$for precipitation model and does not constrain isothermal model, however theseconstraints are mitigated by synchrotron loss time being comparable to CRdiffusion time scales. These bounds are relevant for current numericalsimulations that indicate a significant CR population in CGM of galaxies of MWmass.

Gamma-ray and radio background constraints on cosmic rays in Milky Way circumgalactic medium