تقرير
Anatomy of a z=6 Lyman-{\alpha} emitter down to parsec scales: extreme UV slopes, metal-poor regions and possibly leaking star clusters
| العنوان: | Anatomy of a z=6 Lyman-{\alpha} emitter down to parsec scales: extreme UV slopes, metal-poor regions and possibly leaking star clusters |
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| المؤلفون: | Messa, Matteo, Vanzella, E., Loiacono, F., Bergamini, P., Castellano, M., Sun, B., Willott, C., Windhorst, R. A., Yan, H., Angora, G., Rosati, P., Adamo, A., Annibali, F., Bolamperti, A., Bradač, M., Bradley, L. D., Calura, F., Claeyssens, A., Comastri, A., Conselice, C. J., D'Silva, J. C. J., Dickinson, M., Frye, B. L., Grillo, C., Grogin, N. A., Gruppioni, C., Koekemoer, A. M., Meneghetti, M., Meštrić, U., Pascale, R., Ravindranath, S., Ricotti, M., Summers, J., Zanella, A. |
| سنة النشر: | 2024 |
| المجموعة: | Astrophysics |
| مصطلحات موضوعية: | Astrophysics - Astrophysics of Galaxies |
| الوصف: | We present a detailed JWST/NIRSpec and NIRCam analysis of a gravitationally-lensed galaxy ($\rm \mu=17-21$) at redshift 6.14 magnified by the Hubble Frontier Field galaxy cluster MACS J0416. The target galaxy is overall a typical compact and UV-faint ($\rm M_{UV}=-17.8$) Lyman-$\alpha$ emitter; yet, the large magnification allows the detailed characterisation of structures on sub-galactic (down to few parsec) scales. Prominent optical $\rm H\alpha$, $\rm H\beta$ and [OIII]$\lambda\lambda4959,5007$ lines are spatially resolved with the high spectral resolution grating (G395H, R~2700), with large equivalent widths, EW($\rm H\beta$+[OIII])$\gtrsim1000$ \AA, and elevated ionising photon production efficiencies $\rm log(\xi_{ion}/erg^{-1}Hz)=25.2-25.7$. NIRCam deep imaging reveals the presence of compact rest-UV bright regions along with individual star clusters of sizes $\rm R_{eff}=3-8~pc$ and masses $\rm M\sim2\cdot10^5-5\cdot10^{6}~M_\odot$ These clusters are characterised by steep UV slopes, $\rm\beta_{UV}\lesssim-2.5$, in some cases associated with a dearth of line emission, indicating possible leaking of the ionising radiation, as also supported by a Lyman-$\rm \alpha$ emission peaking at $\rm \sim100~km~s^{-1}$ from the systemic redshift. While the entire system is characterised by low-metallicity, $\sim0.1~Z_\odot$, the NIRSpec-IFU map also reveals the presence of a low-luminosity, metal-poor region with $\rm Z\lesssim2\%~Z_\odot$, barely detected in NIRCam imaging; this region is displaced by $\rm >200~pc$ from one of the UV brightest structures of the system, and it would have been too faint to detect if not for the large magnification of the system. Comment: 19 pages (11 figures, 2 tables) + appendix (3 pages, 4 figures, 1 table). Submitted to A&A; comments are welcome |
| نوع الوثيقة: | Working Paper |
| URL الوصول: | http://arxiv.org/abs/2407.20331 |
| رقم الأكسشن: | edsarx.2407.20331 |
| قاعدة البيانات: | arXiv |
| الوصف غير متاح. |