arXiv subjects

Erik Aquino-Ortíz

Publications and source records attributed to Erik Aquino-Ortíz.

3 recordsLinked to original sources

arXiv2025

Bar Formation in Disc Galaxies: Internal Kinematics and Environmental Influence in MaNGA Galaxies

We explore how the physical properties of disc galaxies relate to the presence of bars using data from the SDSS-IV MaNGA survey. By combining internal kinematical properties and environmental diagnostics, we find that barred galaxies are more frequently associated with centrally concentrated stellar mass distributions (within 1 and 2 effective radii) and exhibit lower values of the stellar angular momentum $λ_{Re}$. At fixed total stellar mass, barred galaxies exhibit: (i) higher stellar mass, and (ii) lower angular momentum, both in their inner regions than their unbarred counterparts. We find a bimodal dependence of the bar fraction on tidal interactions produced by the nearest neighbour. Specifically, the bar fraction peaks in the most isolated galaxies, where bars form unequivocally through internal secular processes, decreases at intermediate interaction strengths, and rises again in the strong interaction regime, likely reflecting the role of dense environments in sustaining or triggering bars. Our results suggest that internal gravitational instabilities are the primary driver of bar formation. External tidal perturbations play a secondary role, capable of triggering or enhancing bar formation in galaxies that are already internally predisposed. Our findings provide robust observational validation of theoretical bar formation and evolution models in galaxies.

astro-ph.GA↗

arXiv2022

SDSS IV MaNGA: Bar pattern speed in Milky Way Analogue galaxies

Most secular effects produced by stellar bars strongly depend on the pattern speed. Unfortunately, it is also the most difficult observational parameter to estimate. In this work, we measured the bar pattern speed of 97 Milky-Way Analogue galaxies from the MaNGA survey using the Tremaine-Weinberg method. The sample was selected by constraining the stellar mass and morphological type. We improve our measurements by weighting three independent estimates of the disc position angle. To recover the disc rotation curve, we fit a kinematic model to the H$_α$ velocity maps correcting for the non-circular motions produced by the bar. The complete sample has a smooth distribution of the bar pattern speed ($Ω_{Bar}=28.14^{+12.30}_{-9.55}$ km s$^{-1}$ kpc $^{-1}$), corotation radius ($R_{CR} = 7.82^{+3.99}_{-2.96}$ kpc) and the rotation rate ($\mathcal{R} = 1.35^{+0.60}_{-0.40}$). We found two sets of correlations: (i) between the bar pattern speed, the bar length and the logarithmic stellar mass (ii) between the bar pattern speed, the disc circular velocity and the bar rotation rate. If we constrain our sample by inclination within $30 \degree < i < 60 \degree$ and relative orientation $20\degree<|PA_{disc}-PA_{bar} |<70\degree$, the correlations become stronger and the fraction of ultra-fast bars is reduced from 20\% to 10\% of the sample. This suggest that a significant fraction of ultra-fast bars in our sample could be associated to the geometric limitations of the TW-method. By further constraining the bar size and disc circular velocity, we obtain a sub-sample of 25 Milky-Way analogues galaxies with distributions $Ω_{Bar}=30.48^{+10.94}_{-6.57}$ km s$^{-1}$ kpc$^{-1}$, $R_{CR} = 6.77^{+2.32}_{-1.91}$ kpc and $\mathcal{R} = 1.45^{+0.57}_{-0.43}$, in good agreement with the current estimations for our Galaxy.

astro-ph.GA↗

arXiv2017

Sloan Digital Sky Survey IV: Mapping the Milky Way, Nearby Galaxies, and the Distant Universe

We describe the Sloan Digital Sky Survey IV (SDSS-IV), a project encompassing three major spectroscopic programs. The Apache Point Observatory Galactic Evolution Experiment 2 (APOGEE-2) is observing hundreds of thousands of Milky Way stars at high resolution and high signal-to-noise ratio in the near-infrared. The Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) survey is obtaining spatially-resolved spectroscopy for thousands of nearby galaxies (median redshift of z = 0.03). The extended Baryon Oscillation Spectroscopic Survey (eBOSS) is mapping the galaxy, quasar, and neutral gas distributions between redshifts z = 0.6 and 3.5 to constrain cosmology using baryon acoustic oscillations, redshift space distortions, and the shape of the power spectrum. Within eBOSS, we are conducting two major subprograms: the SPectroscopic IDentification of eROSITA Sources (SPIDERS), investigating X-ray AGN and galaxies in X-ray clusters, and the Time Domain Spectroscopic Survey (TDSS), obtaining spectra of variable sources. All programs use the 2.5-meter Sloan Foundation Telescope at Apache Point Observatory; observations there began in Summer 2014. APOGEE-2 also operates a second near-infrared spectrograph at the 2.5-meter du Pont Telescope at Las Campanas Observatory, with observations beginning in early 2017. Observations at both facilities are scheduled to continue through 2020. In keeping with previous SDSS policy, SDSS-IV provides regularly scheduled public data releases; the first one, Data Release 13, was made available in July 2016.

astro-ph.GA↗