Spectroscopic study of the HII regions in the NGC 1232 galaxy

Abstract

NGC 1232 is a face-on spiral galaxy that serves as an excellent laboratory for the study of star formation due to its proximity. Recent studies have revealed interesting features about this galaxy: X-ray observations suggest that it recently collided with a dwarf galaxy, however, no apparent remnant is observed. Here we search for evidence of this collision. We used long-slit optical spectra in two different positions obtained with the Goodman spectrograph at the SOAR telescope. We detected 18 HII regions in the north-south direction and 22 HII regions in the east-west direction and a background galaxy, NGC 1232B, for which we present the first redshift measurement and spectral analysis. We used the stellar population fitting technique to study the underlying stellar population and to subtract it from the spectra to measure the emission lines. The emission lines were used to determine the extinction, electron density, chemical abundance, and the star-formation rate gradient of NGC 1232. As is common in spiral galaxies, we found a stellar population gradient with older populations at the central regions and younger ones towards the outskirts, along with a negative oxygen abundance gradient of -0.16 dex/re. Due to the difficulty of measuring important emission lines, the number of objects for the abundance gradient is small, but there is a hint that this galaxy has a broken gradient profile, with a drop towards the center. If the collision caused any disturbance in the galaxy, we believe it would be small and hard to detect with a limited number of objects. From all the other measurements, we found no deviations from a typical spiral galaxy and no significant difference between different directions in the galaxy. The stellar population and emission line analysis of NGC 1232B suggest that it is a starburst galaxy.

arXiv comment18 pages and 16 figures + 14 pages with 14 figures in the appendix. Accepted for publication on A&A

References in corpus (53)

• Stellar population synthesis at the resolution of 2003
• The physical properties of star forming galaxies in the low redshift universe
• [O III]/[N II] as an Abundance Indicator at High Redshift
• SINGS: The SIRTF Nearby Galaxies Survey
• Starburst-driven Mass Loss from Dwarf Galaxies: Efficiency and Metal Ejection
• The Calibration of Mid-Infrared Star Formation Rate Indicators
• Metallicities of 0.3<z<1.0 Galaxies in the GOODS-North Field
• Abundance Gradients and the Formation of the Milky Way
• The O3N2 and N2 abundance indicators revisited: improved calibrations based on CALIFA and Te-based literature data
• A characteristic oxygen abundance gradient in galaxy disks unveiled with CALIFA
• Spectroscopy of Outlying H II Regions in Spiral Galaxies: Abundances and Radial Gradients
• New light on the search for low metallicity galaxies I. The N2 method
• Chemo-spectrophotometric evolution of spiral galaxies: I. The model and the Milky Way
• Evolutionary stellar population synthesis with MILES - II. Scaled-solar and α-enhanced models
• SDSS IV MaNGA - Metallicity and nitrogen abundance gradients in local galaxies
• The history of star-forming galaxies in the Sloan Digital Sky Survey
• Metallicity Gradients in Disks: Do Galaxies Form Inside-Out?
• Semi-empirical analysis of Sloan Digital Sky Survey galaxies: II. The bimodality of the galaxy population revisited
• Stellar Population gradients in galaxy discs from the CALIFA survey
• Mixing Time Scales in a Supernova-Driven Interstellar Medium
• Integral field spectroscopy of a sample of nearby galaxies: II. Properties of the H ii regions
• Shape of the oxygen abundance profiles in CALIFA face-on spiral galaxies
• The MOSDEF Survey: Direct-Method Metallicities and ISM Conditions at $z\sim 1.5-3.5$
• Evidence for Solar Metallicities in Massive Star-forming Galaxies at z>~2
• Chemo-spectrophotometric evolution of spiral galaxies: III. Abundance and colour gradients in discs
• Gas Metallicities in the Extended Disks of NGC 1512 and NGC 3621. Chemical Signatures of Metal Mixing or Enriched Gas Accretion?
• Mapping metallicity variations across nearby galaxy disks
• A VLT study of metal-rich extragalactic H II regions. I. Observations and empirical abundances
• The shape of oxygen abundance profiles explored with MUSE: evidence for widespread deviations from single gradients
• Radial Mixing in Galactic Disks: The Effects of Disk Structure and Satellite Bombardment
• A grid of chemical evolution models as a tool to interpret spiral and irregular galaxies data
• Spiral-induced velocity and metallicity patterns in a cosmological zoom simulation of a Milky Way-sized galaxy
• Upgrading electron temperature and electron density diagnostic diagrams of forbidden line emission
• Stellar Population in LLAGN.I: Ground-based observations
• The SAMI Galaxy Survey: Spatially Resolved Metallicity and Ionization Mapping
• Thermal-Instability-Driven Turbulent Mixing in Galactic Disks: I. Effective Mixing of Metals
• The Chemical Evolution Carousel of Spiral Galaxies: Azimuthal Variations of Oxygen Abundance in NGC1365
• An empirical calibration of nebular abundances based on the sulphur emission lines
• Metallicity Fluctuation Statistics in the Interstellar Medium and Young Stars. I. Variance and Correlation
• Origin and Evolution of the Abundance Gradient along the Milky Way Disk
• Oxygen Abundances and Chemical Evolution in Low Surface Brightness Galaxies
• The Abundance Gradient of NGC 1365: Evidence for a Recently Formed Bar in an Archetype Barred Spiral Galaxy?
• The Effects of Diffuse Ionized Gas and Spatial Resolution on Metallicity Gradients: TYPHOON Two-Dimensional Spectrophotometry of M83
• Evidence of ongoing radial migration in NGC 6754: Azimuthal variations of the gas properties
• The VIRUS-P Exploration of Nearby Galaxies (VENGA): Spatially Resolved Gas-Phase Metallicity Distributions in Barred and Unbarred Spirals
• Mixing and transport of metals by gravitational instability-driven turbulence in galactic discs
• Neutral Gas Distribution and Kinematics of the Nearly Face-on Spiral Galaxy NGC 1232
• Local starburst galaxies and their descendants
• The galaxy-wide distributions of mean electron density in the HII regions of M51 and NGC 4449
• A Spectral Atlas of HII Galaxies in the Near-Infrared
• Star Formation Rate Distribution in the Galaxy NGC 1232
• X-ray discovery of a dwarf-galaxy galaxy collision
• The short bursts in SGR 1806-20, 1E 1048-5937 and SGR 0501+4516

Cited by in corpus (5)

• MaNGA 8313-1901: gas accretion observed in a blue compact dwarf galaxy?
• WEAVE First Light Observations: Origin and Dynamics of the Shock Front in Stephan's Quintet
• Perturbative and numerical approach to plasma strong lensing
• The Supernova Remnant Populations of the galaxies NGC 45, NGC 55, NGC 1313, NGC 7793: Luminosity and Excitation Functions
• X-raying the galaxy pair Arp 41: no collision in NGC 1232 and three ultraluminous sources in NGC 1232A