arXiv subjects

Constanza Muñoz López

Publications and source records attributed to Constanza Muñoz López.

3 recordsLinked to original sources

arXiv2026

Link between the properties of circumgalactic outflows and the recent star formation history of their host galaxies

Galactic outflows play a key role in galaxy evolution, yet their connection to the star formation history of their host galaxies remains poorly constrained. Building on previous work modeling extended Mg II emission of galaxies observed with VLT/MUSE to infer outflow properties, we investigate how these properties depend on the recent SFH. We derive non-parametric SFHs by fitting spectroscopic and photometric data with linear combinations of single stellar population models, and compute star formation rates over different timescales sensitive to recent stochastic bursts. We find moderate correlations between these SFRs (and sSFRs) and the kinematic properties of the outflows, namely maximum velocity and radial acceleration rate. Such correlations are not recovered using SFR tracers based on [O II] luminosity or parametric SFHs, highlighting the importance of capturing bursty star formation on timescales consistent with the traveling time of ejected gas into the circumgalactic medium. Using the extent and kinematics of the Mg II halos, we estimate each galaxy's outflow launching time and compute the SFR averaged over the relevant timescale. We identify a correlation between this SFR and the maximum outflow velocity, although it is not significantly stronger than those obtained using fixed averaging timescales. This suggests that the properties of Mg II halos are shaped by a series of star formation events rather than by a single dominant burst. Lastly, we find faster outflows in galaxies whose recent star formation is dominated by one or a few concentrated episodes, whereas galaxies with star formation spread more evenly over time exhibit slower outflows. These results indicate that the circumgalactic medium acts as a dynamical archive of recent star formation, linking bursty galaxy growth to outflow kinematics and providing a direct observational constraint on feedback models.

astro-ph.GA↗

arXiv2026

Probing the molecular gas content of galaxies in an over-dense group at z~0.7: A test case for environmental quenching

We investigated the impact of group environment on molecular gas reservoirs at an intermediate redshift by observing the CO(2-1) emission from the galaxy group COSMOS-Gr30 at $z \sim 0.7$ with the Institut de Radioastronomie Millimetrique (IRAM) NOrthern Extended Millimeter Array (NOEMA) and 30m telescope. This dense environment, located at the intersection of large-scale cosmic web filaments hosts a large ($\sim 10^{4}$ kpc$^{2}$) ionized gas structure revealed by MUSE. We detect CO emission in four galaxies in the group with a signal-to-noise ratio (S/N) greater than five and derive upper limits for the remaining group members with secure spectroscopic redshifts. Stacked measurements indicate that group galaxies exhibit, on average, molecular gas contents reduced by $\sim 0.5$ dex relative to field scaling relations, corresponding to gas fractions that are $20- 40\%$ of those found in typical main-sequence galaxies. Although the uncertainties are significant, this suggests that environmental processes efficiently deplete molecular gas reservoirs in the galaxies of this group. The 30m observations place an upper limit on the molecular gas associated with the extended ionized structure, $M_{\rm gas} < 2 \times 10^{10} \rm M_\odot$, implying that less than a third of the gas in the intragroup medium is in a cold, star-forming phase. Together, these results show how environmental mechanisms in dense group environments act to remove or suppress molecular gas within galaxies, capturing quenching processes in action.

astro-ph.GA↗

arXiv2026

Stellar angular momentum of intermediate redshift galaxies in MUSE surveys

We quantify the stellar rotation of galaxies by computing the $λ_{R}$ parameter, a proxy for the stellar angular momentum in a sample of 106 galaxies with redshift 0.1 $<$ z $<$ 0.8 and stellar masses from $\sim$10$^{7.5}$ to 10$^{11.8}$ M$_{\odot}$. The sample is located in the CANDELS/GOODS-S and COSMOS fields, and it was observed by various MUSE surveys. We create stellar velocity and velocity dispersion maps using a full-spectrum fitting technique, covering spatially $\sim$2$R_{e}$ for the galaxies. We study the impact of the atmospheric seeing on the spin parameter and apply corrections when pertinent. Through the analysis of the $λ_{R}-ε$ diagram, we notice that the fraction of round and massive galaxies increases with redshift. We lack galaxies with $λ_{R}$ < 0.1 in the sample and we find only one potential, but uncertain, low-mass slow rotator at z $\sim0.3$. Moreover, we do not see an evident evolution or trend in the stellar angular momentum with redshift. We characterize the sample environment using two indicators: a local estimator based on the Voronoi tesselation method, and a global estimator derived by the use of the Friends-of-Friends algorithm. We find no correlation between the environment and $λ_{R}$ given that we are not probing dense regions or massive galaxy structures. We also analyze the kinematic maps of the sample finding that about 40$\%$ of galaxies are consistent with being regular rotators, having rotating stellar discs with flat velocity dispersion maps, while $\sim20\%$ of galaxies have complex velocity maps and can be identified as non-regular rotators in spite of their $λ_{R}$ values. For the remaining galaxies the classification is uncertain. As we lack galaxies with $λ_{R}$< 0.1, we are not able to identify when galaxies become slow rotators within the surveyed environments, area and redshift range.

astro-ph.GA↗