A z$\sim$1 galactic-scale outflow transversally mapped to $\sim$50 kpc through gravitational-arc tomography
Fuente:
arXiv
Salvato in:
| Autori principali: | , , , , , , , , , , , , , , |
|---|---|
| Natura: | Preprint |
| Pubblicazione: |
2026
|
| Soggetti: | |
| Accesso online: | |
| Tags: |
Aggiungi Tag
Nessun Tag, puoi essere il primo ad aggiungerne!!
|
| _version_ | 1866908998703251456 |
|---|---|
| author | Hernández-Guajardo, J. A. Barrientos, L. F. López, S. Johnston, E. J. Ledoux, C. Tejos, N. Afruni, A. Solimano, M. Jullo, E. Cortés-Muñoz, H. Noterdaeme, P. González-López, J. Ormazábal, A. Muñoz-Olivares, F. Berg, T. A. M. |
| author_facet | Hernández-Guajardo, J. A. Barrientos, L. F. López, S. Johnston, E. J. Ledoux, C. Tejos, N. Afruni, A. Solimano, M. Jullo, E. Cortés-Muñoz, H. Noterdaeme, P. González-López, J. Ormazábal, A. Muñoz-Olivares, F. Berg, T. A. M. |
| contents | We report spatially resolved measurements of cool gas traced by Mg II and Fe II absorption in the circumgalactic medium (CGM) of a star-forming galaxy at $z\sim1$ (G1). The fortuitous alignment of a background gravitational arc at z$\sim$2.4 provides seven closely spaced ($\sim$6 kpc) transverse sightlines along the minor axis of G1, probing its CGM out to $\sim$50 kpc. This geometry allows us to detect a galactic-scale outflow simultaneously in down-the-barrel and transverse directions, where blue-shifted Mg II absorption is detected along both types of sightlines, revealing a large-scale, collimated wind. We measure blue-shifted line-of-sight velocities of $v_{\mathrm{los}}$ $\sim$ 62 - 239 km s$^{-1}$ and line-of-sight velocity dispersions $σ_{\mathrm{los}}$ $\sim$ 53 - 133 km s$^{-1}$, suggesting a structure dominated by bulk motion. De-projection of $v_{\mathrm{los}}$ along the minor axis indicates that the outflow material barely approaches the escape velocity and is likely to be gravitationally bound to G1. We constrain an outflow opening angle $θ_c\sim$ 18$^\circ$ - 25$^\circ$, and a mass outflow rate of $ \dot{M}_{\mathrm{out}}$ $\gtrsim$ 0.06 $M_\odot$ yr$^{-1}$, corresponding to a mass loading factor $η$ $\gtrsim$ 0.004, estimated within $\sim$10 - 50 kpc ($\sim$ 0.05 - 0.3 $R_\text{vir}$) of the galaxy centre. Our measurements, combined with previous arc tomography data along the major axis, indicate that normalizing impact parameters by galaxy B-band luminosity substantially reduces scatter in the established anti-correlation between Mg II equivalent width and impact parameter, while also diminishing possible excess of Mg II equivalent width towards the minor axis. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2603_01882 |
| institution | arXiv |
| publishDate | 2026 |
| record_format | arxiv |
| spellingShingle | A z$\sim$1 galactic-scale outflow transversally mapped to $\sim$50 kpc through gravitational-arc tomography Hernández-Guajardo, J. A. Barrientos, L. F. López, S. Johnston, E. J. Ledoux, C. Tejos, N. Afruni, A. Solimano, M. Jullo, E. Cortés-Muñoz, H. Noterdaeme, P. González-López, J. Ormazábal, A. Muñoz-Olivares, F. Berg, T. A. M. Astrophysics of Galaxies We report spatially resolved measurements of cool gas traced by Mg II and Fe II absorption in the circumgalactic medium (CGM) of a star-forming galaxy at $z\sim1$ (G1). The fortuitous alignment of a background gravitational arc at z$\sim$2.4 provides seven closely spaced ($\sim$6 kpc) transverse sightlines along the minor axis of G1, probing its CGM out to $\sim$50 kpc. This geometry allows us to detect a galactic-scale outflow simultaneously in down-the-barrel and transverse directions, where blue-shifted Mg II absorption is detected along both types of sightlines, revealing a large-scale, collimated wind. We measure blue-shifted line-of-sight velocities of $v_{\mathrm{los}}$ $\sim$ 62 - 239 km s$^{-1}$ and line-of-sight velocity dispersions $σ_{\mathrm{los}}$ $\sim$ 53 - 133 km s$^{-1}$, suggesting a structure dominated by bulk motion. De-projection of $v_{\mathrm{los}}$ along the minor axis indicates that the outflow material barely approaches the escape velocity and is likely to be gravitationally bound to G1. We constrain an outflow opening angle $θ_c\sim$ 18$^\circ$ - 25$^\circ$, and a mass outflow rate of $ \dot{M}_{\mathrm{out}}$ $\gtrsim$ 0.06 $M_\odot$ yr$^{-1}$, corresponding to a mass loading factor $η$ $\gtrsim$ 0.004, estimated within $\sim$10 - 50 kpc ($\sim$ 0.05 - 0.3 $R_\text{vir}$) of the galaxy centre. Our measurements, combined with previous arc tomography data along the major axis, indicate that normalizing impact parameters by galaxy B-band luminosity substantially reduces scatter in the established anti-correlation between Mg II equivalent width and impact parameter, while also diminishing possible excess of Mg II equivalent width towards the minor axis. |
| title | A z$\sim$1 galactic-scale outflow transversally mapped to $\sim$50 kpc through gravitational-arc tomography |
| topic | Astrophysics of Galaxies |
| url | https://arxiv.org/abs/2603.01882 |