arXiv subjects

Thiago Bueno-Dalpiaz

Publications and source records attributed to Thiago Bueno-Dalpiaz.

4 recordsLinked to original sources

arXiv2026

Stellar Mass Census of $S^4G$ Local Bars

Bars are stellar structures commonly found in disk galaxies and important agents of secular evolution. Quantifying the stellar mass content of bars provides a physically motivated approach to assess how bar growth depends on galaxy mass and internal structure. We perform a GALFITM multi-band mid-infrared two-dimensional decomposition of 344 barred galaxies from the Spitzer Survey of Stellar Structure in Galaxies ($S^4G$) in the 3.6 and 4.5 $μ$m bands. We estimate the stellar mass associated with each structural component (i.e., disk, bulge, bar, and nuclear point source) and investigate how bar properties correlate with global galaxy characteristics. Our final models consist of 2-4 components per galaxy, with the simplest configuration (disk + bar) typically associated with low-mass systems. We find that more massive galaxies with prominent bulges host more massive bars and higher median bar-to-total stellar mass ratios. These bulges generally present Sérsic indices below 2, consistent with a photometric signature of nuclear stellar disks. Additionally, when we consider the relative bar lengths at a fixed galaxy mass, we find a bimodal distribution where galaxies with bulges host relatively longer bars compared to their bulgeless counterparts. These findings could be the result of different evolutionary paths, possibly linked to different disk formation epochs, allowing bars more time to grow in size and mass. Our study indicates that bar evolution may follow distinct pathways across different galaxy mass regimes, and is likely influenced by secular processes and environmental effects.

astro-ph.GA↗

arXiv2026

The TNG50-SKIRT Atlas: Spatially resolved synthetic galaxies from the ultraviolet to the submillimetre (DR2)

We present the second data release (DR2) of the TNG50-SKIRT Atlas (TSA), a library of synthetic, spatially resolved galaxy observables. The atlas is constructed by post-processing a stellar-mass-complete ($10^{9.8}~{\text{M}}_\odot < M_\star < 10^{12}~{\text{M}}_\odot$) sample of 1154 $z=0$ galaxies from the TNG50 cosmological hydrodynamical simulation with the Monte Carlo radiative transfer code SKIRT. Compared to the first release, TSA DR2 extends the wavelength coverage from the ultraviolet to the submillimetre, including dust emission, and incorporates updated stellar population models together with an improved treatment of dust-enshrouded star-forming regions. The atlas provides spatially resolved spectral energy distributions, broadband images, and physical property maps for multiple viewing orientations, as well as a catalogue of integrated properties enabling direct comparison with unresolved observations. We validate the data products through extensive quality control, including an assessment of Monte Carlo noise, and demonstrate their internal consistency using diagnostic relations between luminosities and star formation rates. TSA DR2 provides a versatile resource for studies of dust attenuation and emission, star formation tracers, galaxy morphology, and multi-wavelength scaling relations across spatial scales. The atlas and associated data products are publicly released and are intended to support a wide range of observationally oriented studies of galaxy evolution.

astro-ph.GA↗

arXiv2026

The detectability of bars at high redshift: a case study using Euclid-like mock observations of TNG50 simulated galaxies

Modern surveys such as Euclid report a decline in the fraction of barred galaxies from the local Universe to $z \sim 1$, whereas the TNG50 simulation predicts higher bar fractions, in tension with observations. This discrepancy may be due to observational biases in bar detectability when comparing simulations with observations. We present a proof-of-concept study quantifying how Euclid-like observational conditions affect bar detectability in TNG50. We analysed the entire galaxy sample at $z = 0.5$ and highlight one borderline case with a bar length of 2.1 kpc and bar strength $A_2 = 0.4$. Synthetic images were produced with Monte Carlo radiative transfer and realistic post-processing, and analysed with ellipse fitting and Fourier decomposition, as well as the recently constructed Zoobot analysis. Results were compared to idealised, noise-free stellar mass maps. In the illustrative case the bar is clearly detected in the mass map and remains visible in the Euclid VIS $I_{\rm E}$ filter, where Zoobot also classifies it as barred, but becomes undetectable in $Y_{\rm E}$ and in the VIS-NISP RGB composite, with all methods failing outside VIS. Extending to the full $z = 0.5$ sample, Zoobot recovers only 31/141 galaxies, while $A_2$ and ellipse fitting perform better (80/141 and 67/141) but still miss many short or weak bars. When non-detections are counted as unbarred, the bar fraction of 44 percent falls to $12\!-\!33$ percent depending on the method. These results demonstrate the strong impact of observational effects on bar detectability and motivate bar-fraction estimates which incorporate realistic instrumental conditions across redshift in cosmological simulations.

astro-ph.GA↗

arXiv2025

Bar properties as a function of wavelength in TNG50: analysis of mock images

Recent studies used TNG50 galaxies to study bar formation, evolution, and properties like length, strength, and pattern speed. In simulations, these are typically derived from particle positions and mass distribution, neglecting stellar light and extinction effects. However, observational studies indicate that bar appearance depends on wavelength. To test whether this dependence exists in TNG50 at $z \sim 0$, we analysed 50 strongly barred galaxies using mock images from SKIRT radiative transfer simulations covering infrared to ultraviolet filters (Spitzer 3.6 um, SDSS i, r, g, S-PLUS J0378, GALEX NUV, and GALEX FUV). Bar ellipticity and length were measured via ellipse fitting. Ellipticity generally increases by 6 percent from 3.6 um to g band, and by 9 percent to J0378 band. On average, TNG50 bars cannot be said to be longer in bluer filters when the entire sample is used. However, the trend is detected when only star-forming galaxies are considered. In this star-forming subsample, bar length increases by 10 percent from 3.6 um to g band, and by 17 percent to J0378 band; moreover, the bar can appear up to 20${-}$30 percent longer in bluer mocks than in the mass map. Over 90 percent of bars vanish in UV due to minimal emission by dominant stellar populations. We reproduced the bar properties morphological dependence phenomenon using age-filtered mass maps, where older stars form shorter, rounder bars, and younger stars generate longer, more elliptical ones. TNG50 bars exhibit a wavelength-dependent trend similar to observations: bars appear more elliptical and longer in bluer filters, with this effect being stronger in star-forming galaxies.

astro-ph.GA↗