arXiv subjects

Simon B. De Daniloff

Publications and source records attributed to Simon B. De Daniloff.

6 recordsLinked to original sources

arXiv2026

The OTELO Survey: The main sequence of low-mass galaxies

This paper describes the relationship between the star formation rate and the stellar mass, the so-called main sequence (MS), of low-mass galaxies at three different redshifts from the OTELO survey. In particular, we study Halpha at z=0.38, [OIII] at z=0.83, and [OII] at z=1.43 emission line galaxies (ELGs). This is done to characterise the properties of low-mass ELGs. We fitted the spectral energy distribution (SED) of each emitter and obtained the stellar masses, the total infrared luminosity, and the star formation rate. We found that 100% of the Halpha emitters and about 90% of the [OIII] and [OII] emitters are low-mass galaxies (< 1E10M_sun). We generated a MS for each redshift regime, employing all galaxies and binning them in stellar mass. We obtained the parameters of the fit (turnover mass and slope of the low-mass regime) and compared them to results from the literature. We found that the colour-magnitude method employed to select ELGs leaves out a significant number of them. We also found that the whole sample contains few luminous infrared galaxies and no ultra-luminous infrared galaxies. We also found that the lack of infrared constraints in the input SEDs may generate problems when determining the total infrared luminosity. When comparing the MS obtained for our sample of low-mass ELGs with those from the bibliography, we found, in general, very good agreement. We can consider the MS to be almost the same for the relatively unexplored regime of low-mass galaxies. However, the turnover mass obtained by this work is higher for all redshifts compared with the ones from the literature. We suggest that this is an effect of the different methods and samples used in the generation of the MS compared to those of the bibliography.

astro-ph.GA↗

arXiv2026

The CAVITY project. The spatially resolved SFR of galaxies in voids

The mass in the Universe is distributed non-uniformly, originating the Large Scale Structure (LSS), characterised by clusters, filaments, walls and voids. Galaxies in voids are bluer, later type, less massive, and have slower evolution than galaxies in denser environments. The effect of the void environment on properties such as star formation rate (SFR) is still under discussion. We tackle this by estimating spatially-resolved SFR from extinction-corrected Halpha luminosities of 220 void galaxies from the CAVITY survey. These observations consist of optical integral field unit data cubes from the PMAS/PPaK spectrograph at Calar Alto Observatory. We measure the continuum-subtracted emission lines to obtain maps of SFR, specific star formation rate (sSFR) and extinction. We assess global properties and radial profiles up to 2 half-light radii. We compare with galaxies in filaments and walls from the CALIFA survey using the same methodology, building a control sample matched in morphology and stellar mass. We find no significant differences in SFR and sSFR, although void galaxies tend to have larger SFR, especially for early spirals. This effect is present for Sa galaxies at all galactocentric distances, and in the outer parts of late-type spirals, evidencing slower transition to quiescence and less evolved discs. Void late-type galaxies have lower extinction. Using extinction normalised by stellar mass surface density as a proxy for gas mass fraction, we find it larger for void early spirals, especially in outer regions. This indicates the effect of the void environment on the transition from star forming to passive.

astro-ph.GA↗

arXiv2025

GLACE survey: OSIRIS/GTC multi-object spectroscopy of the rich galaxy cluster ZwCl 0024.0+1652 at z~0.4. III. The mass-SFR relation and the quenching of cluster galaxies

Galaxy clusters are among the largest and densest structures in the Universe. Their high density generally increases the suppression of star formation, known as quenching, altering galaxy properties. We study the quenching of emission-line galaxies (ELGs) in the rich cluster ZwCl 0024.0+1652 (Cl0024) at redshift $z\sim0.4$, aiming to determine if and how star formation is suppressed. Using multi-object spectroscopy from the GLACE survey, we extracted fluxes and redshifts of [O II]$λ\lambda3727,3729$, $\mathrm{Hβ}$, and [O III]$\lambda5007$ emission lines to derive star formation rates (SFRs) for 173 ELGs. We also performed spectral energy distribution fitting to obtain key evolutionary parameters such as stellar masses ($M_\star$) and the 4000 Å break ($D4000$) index. We derived the $M_\star-\mathrm{SFR}$ relation for 98 star-forming galaxies (SFGs), finding 34.7% exhibit suppressed SFRs in the cluster, compared to 11.0% in the field. While the SFRs show no significant variation with local density, the fraction of SFGs is 1.55 times higher in the cluster outskirts than in intermediate-density regions. The specific SFR decreases strongly with $D4000$ for active SFGs but remains constant for suppressed galaxies. The fraction of suppressed galaxies in the infall region is 2.6 times higher than in the core, especially in the infalling structure B of the cluster. The cluster's total mass does not appear to be a key factor in SFG quenching. Star formation in Cl0024 galaxies is suppressed by the dense cluster environment. This suppression is evident in SFG fractions and parameters tracing long-term evolution, indicating prolonged quenching. The SFGs preferentially reside in low-density regions, while suppressed galaxies dominate the infall region, supporting a 'delayed-then-rapid' quenching scenario.

astro-ph.GA↗

arXiv2025

Starburst galaxies in the Hydra I cluster

We present a new catalog of 196 galaxies of the nearby Hydra I cluster out to $\sim$1.75$\rm r_{200}$, consisting of broad u,g,r,i,z along with narrowband H$α$ measurements. These deep optical images were obtained with the DECam camera (CTIO) and reach down to a surface brightness limit of $μ( 3σ;10''\times10'')$=26.9 mag $\rm arcsec^2$ in the g band. We also report the HI properties for 89 cluster members detected with MeerKAT. A color magnitude diagram (CMD) shows a bimodal distribution typical of a cluster population, more evolved than those found in isolation. We combine optical H$α$ and WISE infrared data to compare the star formation history at two distinct timescales. Differences in the star forming activity depicted by both populations manifest as starburst in 24 found members. Of these, 18 starburst galaxies have neutral gas measurements, and show disturbed HI disks that suggest an environmentally-triggered boost in star formation within the last 10$^7$ yrs. Processes such as ram pressure stripping or tidal interactions may underlie their enhanced star-forming activity and asymmetric disks. Since Hydra's dynamical history is unclear, we examine the spatial and velocity distribution of the sample. We reveal a possible link between the large scale structure feeding the Hydra I cluster and the heightened star-forming activity of the starburst galaxies. This feeding pattern matches the few substructure that has been identified in Hydra in previous works, and may explain its origin. Our results portray a picture of a cluster with an evolved nature, plus a population of new infalling galaxies that manifest the impact of their first contact with the cluster environment through star formation, color, morphology and gas content transformations.

astro-ph.GA↗

arXiv2024

CAVITY: Calar Alto Void Integral-field Treasury surveY. I. First public data release

The Calar Alto Void Integral-field Treasury surveY (CAVITY) is a legacy project aimed at characterising the population of galaxies inhabiting voids, which are the most under-dense regions of the cosmic web, located in the Local Universe. This paper describes the first public data release (DR1) of CAVITY, comprising science-grade optical data cubes for the initial 100 out of a total of $\sim$300 galaxies in the Local Universe ($0.005 < z < 0.050$). These data were acquired using the integral-field spectrograph PMAS/PPak mounted on the 3.5m telescope at the Calar Alto observatory. The DR1 galaxy sample encompasses diverse characteristics in the color-magnitude space, morphological type, stellar mass, and gas ionisation conditions, providing a rich resource for addressing key questions in galaxy evolution through spatially resolved spectroscopy. The galaxies in this study were observed with the low-resolution V500 set-up, spanning the wavelength range 3745-7500 Å, with a spectral resolution of 6.0 Å (FWHM). Here, we describe the data reduction and characteristics and data structure of the CAVITY datasets essential for their scientific utilisation, highlighting such concerns as vignetting effects, as well as the identification of bad pixels and management of spatially correlated noise. We also provide instructions for accessing the CAVITY datasets and associated ancillary data through the project's dedicated database.

astro-ph.GA↗

arXiv2024

GLACE survey: OSIRIS/GTC tuneable imaging of the galaxy cluster ZwCl 0024.0+1652 II. The mass--metallicity relationship and the effect of the environment

In this paper, we revisit the data for the galaxy cluster ZwCl 0024.0+1652 provided by the GLACE survey and study the mass--metallicity function and its relationship with the environment. Here we describe an alternative way to reduce the data from OSIRIS tunable filters. This method gives us better uncertainties in the fluxes of the emission lines and the derived quantities. We present an updated catalogue of cluster galaxies with emission in H$α$ and [N\,{\sc{ii}}] $λλ$6548,6583. We also discuss the biases of these new fluxes and describe the way in which we calculated the mass--metallicity relationship and its uncertainties. We generated a new catalogue of 84 emission-line galaxies with reliable fluxes in [N\,{\sc{ii}}] and H$α$ lines from a list of 174 galaxies. We find a relationship between the clustercentric radius and the density of galaxies. We derived the mass--metallicity relationship for ZwCl 0024.0+1652 and compared it with clusters and field galaxies from the literature. We find a difference in the mass--metallicity relationship when compared to more massive clusters, with the latter showing on average higher values of abundance. This could be an effect of the quenching of the star formation, which seems to be more prevalent in low-mass galaxies in more massive clusters. We find little to no difference between ZwCl 0024.0+1652 galaxies and field galaxies located at the same redshift.

astro-ph.GA↗