Unveiling gas kinematics and stellar populations in H ii regions inside the low-metallicity dwarf nearby galaxy SDSSJ0859 + 3923 with MEGARA at the GTC
Year: 2024
Type: article
Abstract: ABSTRACT In this study, we present Integral Field Unit observations of the galaxy SDSSJ0859 + 3923, utilizing the MEGARA (Multi Espectrógrafo en GTC de Alta Resolución para Astronomía) instrument on the GTC (Gran Telescopio Canarias) 10.4m telescope. These observations were conducted in two distinct spectral ranges: 4332–5222 Å and 6097–7345 Å, with a high resolving power (R$_\mathrm{FWHM}$$\sim 6\, 000$), and spatial resolution of 25 pc, considering the galaxy’s distance of 8.5 Mpc. Our observations have identified five H ii regions, whose precise positions were determined using data from the Wide Field Camera 3 (ultraviolet and visible) of the Hubble Space Telescope, WFC3-UVIS/HST, archive images, where we also detected the associated blue underlying continuum linked to the ionized knots. A detailed kinematic analysis of these regions revealed low-velocity dispersion values (around 10 km s$^{-1}$) in four H ii regions, indicating a lack of significant turbulent events. In the fifth region, we observed a peak in velocity dispersion reaching 40 km s$^{-1}$, which we interpret as the result of hot star winds and/or a recent type-II supernova explosion. We have conducted a comprehensive spectral analysis of the H ii regions, obtaining emission-line fluxes that enabled us to confirm the oxygen abundance (12 + log(O/H) = 7.41 $\pm$ 0.15) and, using popstar models, to constrain the age and mass of the ionizing young clusters.
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $3,012
Awards: G1105844351, G114353912, G1175115578, G121809054, G1358376193, G1397760875, G1496818916, G1622782223, G1650125035, G1855990336, G1888088267, G2262748287, G2309174360, G2660406951, G2673512141, G279363373, G300979063, G3110389281, G34346518, G3480869486, G3518538256, G3690828678, G3983401309, G410571670, G4212894969, G425668148, G430777504, G4485413849, G451917667, G4526231891, G491712853, G5080475149, G526084217, G5404395142, G5421974903, G5539308778, G5555131222, G5635532810, G5967599077, G624877701, G6298273575, G6574345672, G6865020320, G7058120361, G7084143925, G7239663274, G7434936867, G7473715904, G7805626310, G7863371703, G7979596951, G8053898782, G8181105605, G8497050386, G8684520763, G8870178939, G8920660035, G8974602263, G897484643, G929308097, G99296377
OpenAlex ID: W4404028257