تقرير
Investigation of the Radial Profile of Galactic Magnetic Fields using Rotation Measure of Background Quasars
| العنوان: | Investigation of the Radial Profile of Galactic Magnetic Fields using Rotation Measure of Background Quasars |
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| المؤلفون: | Sharma, Paras, Burman, Shivam, Malik, Sunil, Singh, Suprit |
| سنة النشر: | 2024 |
| المجموعة: | Astrophysics |
| مصطلحات موضوعية: | Astrophysics - Astrophysics of Galaxies, Astrophysics - Cosmology and Nongalactic Astrophysics |
| الوصف: | Probing magnetic fields in high-redshift galactic systems is crucial to investigate galactic dynamics and evolution. Utilizing the rotation measure of the background quasars, we have developed a radial profile of the magnetic field in a typical high-$z$ galaxy. We have compiled a catalog of 59 confirmed quasar sightlines, having one intervening Mg \rom{2} absorber in the redshift range $0.372\leq z_{\text{abs}} \leq 0.8$. The presence of the foreground galaxy is ensured by comparing the photometric and spectroscopic redshifts within $3 \sigma_{z-\text{photo}}$ and visual checks. These quasar line-of-sights (LoS) pass through various impact parameters (D) up to $160$ kpc, covering the circumgalactic medium of a typical Milky-Way type galaxy. Utilizing the residual rotation measure (RRM) of these sightlines, we estimated the excess in RRM dispersion, $\sigma_{\text{ex}}^{\text{RRM}}$. We found that the sightlines having impact parameters $\text{D} \leq 50$ kpc and $\text{D} > 50$ kpc, $\sigma_{\text{ex}}^{\text{RRM}}$ show significant difference from $24.86 \pm 3.08$ rad m$^{-2}$ to $16.34 \pm 1.88$ rad m$^{-2}$ respectively. The profile of $\sigma_{\text{ex}}^{\text{RRM}}$ with D exhibits a decreasing trend. We translated $\sigma_{\text{ex}}^{\text{RRM}}$ to average LoS magnetic field strength, $\langle B_{\|}\rangle$ by considering a typical electron column density. Consequently, the anti-correlation is sustained, resulting in a decreasing magnetic field profile. This suggests a clear indication of varying magnetic field from the disk to the circumgalactic medium. This work provides a methodology that, when applied to ongoing and future radio polarisation surveys such as LOFAR and SKA, promises to significantly enhance our understanding of magnetic field mapping in galactic systems. Comment: 10 pages, 8 figures |
| نوع الوثيقة: | Working Paper |
| URL الوصول: | http://arxiv.org/abs/2405.09623 |
| رقم الأكسشن: | edsarx.2405.09623 |
| قاعدة البيانات: | arXiv |
| الوصف غير متاح. |