In these observations, the 1″ slit was aligned with the major axis, PA(slit) = 83deg, and the total exposure time was 75 min also the target was exposed in the orientation through the neighbouring dwarf galaxy, PA(slit) = 135deg, with the exposure time of 45 min. UGC 5936 was observed on February 28, 2014. Our long-slit spectral observations were made with a multi-mode focal reducer SCORPIO-2 ( Afanasiev & Moiseev 2011) at the prime focus of the Russian 6 m telescope of the Special Astrophysical Observatory, Russian Academy of Sciences. (2018) and NGC 4513 is described by Proshina et al.
Arc rings schmidt bender series#
This paper is a part of our series about the origin of star-forming rings in S0 galaxies earlier NGC 6534 and MCG 11-22-015 are described by Sil’chenko et al. The distance to the galaxy is 108 Mpc and the linear scale is about 0.5 kpc per arcsec (NED). The galaxy was observed in a 21 cm line and was found to be a rather gas-rich S0, with 1.38 × 10 9 M ⊙ of the neutral hydrogen ( Wang et al. In Ilyina & Sil’chenko (2011), we noted that the UV ring of this galaxy matches the geometry of the optical blue ring. The optical-band ring and the first spectral results for this galaxy were reported by Kostyuk (1975) and Kostyuk et al. In this Letter, we consider UGC 5936, which is a luminous (R)SA0 + galaxy located in the northern sky ( M H = −24.86 NASA/IPAC Extragalactic Database NED). The gas origin in S0s is still controversial even less is known about star formation in S0s providing stellar ring structures.
Among the outer stellar rings, about 50% are also seen in ultraviolet (UV) ( Kostiuk & Sil’chenko 2015) thereby betraying recent star formation and probably being expected to contain some amount of gas to fuel this star formation. (2009), only 46% of S0s show some signs of bars against 64%–69% among spirals, and these bars are mostly weak ( Buta et al. Just the occurrence of bar structures falls in S0s with respect to spiral galaxies according to statistics by Laurikainen et al. This contrasts with how this phenomenon has been commonly treated in a wider sample of spiral ringed galaxies ( Buta 1986). In most cases, the nature of these rings cannot be attributed to bar resonances. Surface photometry reveals that about 50% of S0-S0/a galaxies possess outer stellar rings ( Comerón et al. As mentioned by de Vaucouleurs (1959) in reference to Hubble, there are two groups of S0 objects: those with smooth lenses and envelopes and those showing some structure in the envelope in the form of a dark zone and ring. Rings are common attributes of S0 galaxies by the definition of this morphological type. Key words: galaxies: elliptical and lenticular, cD / galaxies: evolution / galaxies: structure / galaxies: star formation / galaxies: interactions / galaxies: individual: UGC 5936 The accretion being smooth and laminar provides a favourable condition for star formation ignition this is a consequence of the satellite location and rotation in the plane of the stellar disc of the host galaxy. The whole morphology of the HI distribution implies current accretion of the cold gas from the satellite onto the outer disc of UGC 5936. Star formation in the ring is rather prolonged and its intensity corresponds to the current HI content of UGC 5936 (to the Kennicutt-Schmidt relation). The ionised gas of the ring is excited by young stars and has solar metallicity.
We also proved the spatial proximity of the south-eastern dwarf satellite to UGC 5936 and measured its gas metallicity. After inspecting the gas excitation in the ring using line ratio diagnostic diagrams and having ensured that it is ionised mostly by young stars, we determined the gas oxygen abundance with popular strong-line methods. We measured gas and star kinematics by applying long-slit spectroscopy along the major axis of UGC 5936, as well as Lick indices for the main body of the galaxy and strong emission-line flux ratios in the ring. The luminous S0 galaxy with a large ring, UGC 5936, is studied in this work. We try to clarify the nature of this phenomenon and the difference between this occurrence and star formation in spiral galaxies. 13, 119234 Moscow, RussiaĮ-mail: Astrophysical Observatory of the Russian Academy of Sciences, Nizhnij Arkhyz 369167, RussiaĮ-mail: Even though S0 galaxies are usually thought to be ‘red and dead’, they often demonstrate star formation organised in ring structures. Sternberg Astronomical Institute of the Lomonosov Moscow State University, University av.
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