arXiv subjects

P. Vásquez-Bustos

Publications and source records attributed to P. Vásquez-Bustos.

8 recordsLinked to original sources

arXiv2026

CAVITY: Calar Alto Void Integral-field Treasury surveY: II. Second public data release

Studying galaxy evolution under the unique environmental conditions of cosmic voids provides an opportunity to disentangle the role of the large-scale environment in shaping mass assembly (both baryonic and dark matter), regulating galaxy physical properties, and driving the transformation from star-forming to quiescent systems. We present the second public data release (DR2) of the Calar Alto Void Integral-field Treasury Survey (CAVITY), an ongoing legacy programme designed to study void galaxies (VGs) across a range of nearby ($0.005 \leq z \leq 0.050$) voids with different sizes and dynamical stages, providing 200 science-grade optical integral-field spectroscopy (IFS) data cubes. By doubling the number of galaxies relative to DR1 while maintaining the same selection criteria, DR2 significantly increases the dataset's statistical power, enabling more robust characterization of galaxy properties and their correlations with environment. The observations were obtained with the PMAS/PPAK spectrograph on the 3.5-m Calar Alto telescope using the V500 configuration, covering the optical spectral range of 3745-7500 A at a resolution of 6 A (FWHM). The DR2 VG sample spans a broad range of stellar masses, morphologies, colours, and gas ionisation properties. We describe the sample selection, observing strategy, data reduction pipeline, quality-control procedures, and the public access to the CAVITY datasets and associated ancillary data on the survey's database. In addition, we present a characterisation of the large- and local-scale environments of CAVITY galaxies, showing that the 15 surveyed voids encompass a wide variety of sizes, galaxy richness, galaxy populations, and local structures, including galaxy groups. This release comprises 200 IFS data cubes, publicly available together with the master catalogues at the survey's dedicated webpage: https://cavity.caha.es/data/dr2/.

astro-ph.GA↗

arXiv2026

ALMA CO-CAVITY II. Resolved Scaling Relations in Void Galaxies

Scaling relations involving star formation rates (SFRs), molecular gas mass, and stellar mass are key to understand galaxy evolution, and have previously been explored at resolved scales. However, they have not been examined with particular emphasis on the large-scale environments (LSEs). In this work, we study the resolved Schmidt-Kennicutt relation (rSK), molecular gas main sequence (rMGMS) and star-forming main sequence (rSFMS) from a sample of 41 void galaxies (VGs) residing in the least dense regions of the Universe. Using high-resolution interferometric CO(1-0) data and optical IFU data from the ALMA CO-CAVITY and CAVITY surveys at scales of 2.5" (0.8-2.1 kpc), we study these relations for the full sample as well as for individual galaxies in voids. We fit the relations, finding a similar parametrisation as that used for galaxies from all LSEs. However, the rMGMS is the tightest of the three relations ($σ_{rMGMS}=0.16$ dex, $σ_{rSK}=0.21$ dex, and $σ_{rSFMS}=0.24$ dex), unlike in other samples. We find that a large source of deviations in the relations comes from galaxy-to-galaxy variations. However, the rMGMS is less affected by these variations. It has been suggested that the rMGMS arises from the concentration of molecular gas within the gravitational potential set by the stellar content and dark matter. We hypothesise that deviations from the rMGMS trace changes in the gravitational potential occurring on longer time-scales, whereas deviations in the rSK and the rSFMS are driven by more rapid variations in the SFR. This distinction is particularly relevant for our sample of VGs because the 41 ALMA CO-CAVITY VGs are more isolated than galaxies in other LSEs, and therefore are less affected by events that can significantly alter the gas distribution or trigger SF on short time-scales. In this sense, the rMGMS is likely the most stable of these relations over time.

astro-ph.GA↗

arXiv2026

Galaxy groups within voids

In this work, we aim to identify and characterise a sample of galaxy groups within voids in the local Universe (z\,<\,0.08), taking into account the peculiarities of these vast and empty structures. The void galaxies used in this study are selected from a well-defined void galaxy sample, from which the parent sample of the Calar Alto Void Integral-field Treasury surveY (CAVITY) legacy project was drawn. To identify galaxy groups, we applied a fiends-of-friends (FoF) like group finder algorithm to the selected sample, ensuring a certain degree of gravitational binding among group members. The same algorithm has been applied to identify a control sample of groups not in clusters nor voids, referred as NCNV groups. The catalogue of groups consists on 1367 physically bound groups, with a total of 3040 galaxies, plus 14672 galaxy singlets. Most of the galaxies in voids are singlets (59\%), in contrast, most of the NCNV galaxies in the control sample are in groups (60\%). To consider the dynamical stage of the groups we used the parameters harmonic radius ($\rm R_H$), radial velocity dispersion ($\rm σ_{v_r}^2$), dimensionless crossing time ($\rm H_0 t_c$), and group virial mass ($\rm M_{vir}$). We also used the total optical ($r$-band) luminosity, L$_r$, to estimate the mass-to-light ratio ($\rm M/L$) of the groups. We studied the relations of void properties and these parameters with the group richness. Galaxy groups can be found in any void in the local Universe, with no dependency of group richness on the density of voids. The densest groups in the studied sample of voids are composed of six galaxies, therefore, voids generally contain small groups, in comparison to denser structures such as filaments, walls, and galaxy clusters. Galaxy groups within voids are typically loose groups, in an early stage of their evolution.

astro-ph.GA↗

arXiv2026

ALMA CO-CAVITY I. Resolved Molecular Gas in Void Galaxies

The environment plays a key role in galaxy evolution, yet it remains unclear how detailed molecular gas properties and their connection to star formation and stellar content are influenced by both large-scale and local environments. Here we introduce the ALMA CO-CAVITY project, the first interferometric CO(1-0) survey of a large sample of 41 void galaxies (VGs) to characterise in detail their molecular gas properties. It is built over the CAVITY project, offering optical integral field unit (IFU) data, enabling a direct, pixel-to-pixel comparison between molecular gas (from ALMA), star formation, and stellar properties, as well as the derivation of their scaling relations. In this work we present ALMA data products for our sample, containing data cubes, moment maps and position-velocity diagrams at angular resolutions of 1 arcsec. We also present molecular gas, stellar mass, and star formation rate surface density maps at a common resolution of 2.5 arcsec. We contextualise our sample against representative unresolved and resolved surveys. While our sample provides a good representation of the VG population and follows the distribution of key properties seen in star-forming galaxy samples, galaxies included in resolved studies from the literature tend to be more massive, less isolated, and located in denser large-scale environments. We present global scaling relations for the ALMA CO-CAVITY sample and find that the molecular gas main sequence exhibits the smallest scatter (0.21 dex), followed by the Schmidt-Kennicutt relation and the star-forming main sequence. From integrated properties alone, we find that these scaling relations for VGs are compatible with those for denser environments. This paper lays the foundation for forthcoming studies exploiting this unique dataset.

astro-ph.GA↗

arXiv2025

The role of supercluster filaments in shaping galaxy clusters

In a hierarchical $Λ$CDM Universe, cosmic filaments serve as the primary channels for matter accretion into galaxy clusters, influencing the shape of their dark matter halos. We investigate whether the elongation of galaxy clusters correlates with the orientation of surrounding filaments, providing the first observational test of this relationship in large supercluster regions. We identified and characterized cosmic filaments in two dimensions within the two superclusters that are part of the low-redshift sub-survey of the Chilean Cluster Galaxy Evolution Survey (CHANCES): the Shapley supercluster and the Horologium-Reticulum supercluster. We analyzed the alignment between filament directions -- traced by galaxy distributions -- and the triaxiality of cluster gravitational potentials -- traced by X-ray emission- using publicly available optical and X-ray data. We have found that most (82%) of the X-ray clusters are associated with and interconnected by the optically detected filaments. The clusters-filaments alignment analysis shows that the elongation of most clusters is well aligned with nearby filaments, providing observational confirmation of theoretical predictions, with the alignment progressively reducing at larger cluster-centric distances ($> 1.6 r_{200}$). Overall, our results support the notion that filaments are the main source of galaxy accretion at redshift below 0.1 and additionally provide evidence that matter accretion through filaments shapes the gravitational potential of galaxy clusters. We propose this measurement as a simple observational proxy to determine the direction of accretion in clusters, which is key to understanding both galaxy evolution and the merger history of galaxy clusters.

astro-ph.CO↗

arXiv2025

A MaNGA view of isolated galaxy mergers in the star-forming Main Sequence

In this work we carry out an analysis of star-formation and nuclear activity in the different stages during a galaxy merger identified in isolated systems (isolated galaxies, isolated pairs, and isolated triplets) using integral field spectroscopy from the SDSS-IV/MaNGA project. We classify galaxies into close pairs, pre-mergers, mergers, and post-mergers (including galaxies with post-starburst spectroscopic features), for a total sample of 137 galaxies. We constrained their star formation history from spectrophotometric SED fitting with CIGALE, and used spatially resolved WHAN diagrams, with other MaNGA data products to explore if there is any connection of their physical properties with their merging stage. In general, galaxies show characteristic properties intrinsically related to each stage of the merger process. Galaxies in the merger and post-merger stages present higher star formation activity (measured by their integrated sSFR). In the merger stage, the fraction of strong AGN spaxels is comparable to the fraction of spaxels with pure star-formation emission, with no difference between AGN activity in close pairs and strongly interacting galaxies with the same stellar mass. Our results support the scenario where galaxy interactions trigger star-formation and nuclear activity on galaxies. Nonetheless, AGN has a minor role in quenching galaxies following a merger, as AGN feedback might not have had sufficient time to inhibit star formation. In addition, we found that the quenching process in post-mergers galaxies with post-starburst emission is happening outside-in, being an observational proof of the effect of interactions on the quenching process. The transforming processes after a recent major galaxy interaction may happen slowly on isolated environments, where the system evolves in a common dark matter halo without any perturbation of external galaxies.

astro-ph.GA↗

arXiv2022

Understanding the role of morphology and environment on the dynamical evolution of isolated galaxy triplets

The environment where galaxies reside affects their evolutionary histories. Galaxy triplets (systems composed of three physically bound galaxies) constitute one of simplest group of galaxies and are therefore excellent laboratories to study evolutionary mechanisms where effects of the environment are minimal. We present a statistical study of the dynamical properties of isolated galaxy triplets as a function of their local and large scale environments. To explore the connection of the dynamical evolution on the systems with the evolution of the galaxies composing the triplets, we consider observational properties as morphology and star formation rate (SFR). We used the SDSS-based catalog of Isolated Triplets (SIT), which contains 315 triplets. We classified each triplet according to galaxy morphologies and defined a parameter $Q_{trip}$ to quantify the total local tidal strengths in the systems. To quantify the dynamical stage of the system we used the parameters harmonic radius, $R_H$, velocity dispersion, $σ_{vr}$, crossing time, $H_0t_c$, and virial mass, $M_{vir}$. Triplets composed of three early type galaxies present smallest $R_H$, indicating that they are in general more compact than triplets with one or more late type galaxies. Among triplets with low values of $R_H$ and $H_0t_c$, SIT triplets with $Q_{trip}$<-2 are relaxed systems, more dynamically evolved, while triplets with $Q_{trip}$>-2 show compact configurations due to interactions within the system, such as on-going mergers. We found that there is no dominant galaxy in triplets in terms of properties of stellar populations such as global colour and SFR. Moreover, the global SFR in isolated triplets composed of two or more early-type galaxies increases with the stellar mass ratio of the galaxies with respect to the central galaxy, therefore the system is globally 'rejuvenated'.

astro-ph.GA↗

arXiv2022

SIT 45: An interacting, compact, and star-forming isolated galaxy triplet

The merging system SIT 45 (UGC 12589) is an unusual isolated galaxy triplet, consisting of three merging late-type galaxies, out of 315 systems in the SIT (SDSS-based catalogue of Isolated Triplets). The main aims of this work are to study its dynamical evolution and star formation history (SFH), as well as its dependence on its local and large-scale environment. To study its dynamics, parameters such as the velocity dispersion ($σ_{v}$), the harmonic radius ($R_{H}$), the crossing time ($H_0t_c$), and the virial mass ($M_{vir}$), along with the compactness of the triplet ($S$) were considered. To constrain the SFH, we used CIGALE to fit its observed spectral energy distribution using multi-wavelength data from the ultraviolet to the infrared. According to its SFH, SIT 45 presents star-formation, where the galaxies also present recent ($\sim $200 Myr) star-formation increase, indicating that this activity may have been triggered by the interaction. Its dynamical configuration suggests that the system is highly evolved in comparison to the SIT. However this is not expected for systems composed of star-forming late-type galaxies, based on observations in compact groups. We conclude that SIT 45 is a system of three interacting galaxies that are evolving within the same dark matter halo, where its compact configuration is a consequence of the on-going interaction, rather than due to a long-term evolution (as suggested from its $H_0t_c$ value). We consider two scenarios for the present configuration of the triplet, one where one of the members is a tidal galaxy, and another where this galaxy arrives to the system after the interaction. Both scenarios need further exploration. The isolated triplet SIT 45 is therefore an ideal system to study short timescale mechanisms ($\sim 10^8$ years), such as starbursts triggered by interactions which are more frequent at higher redshift.

astro-ph.GA↗