NGC 1672 is a barred spiral galaxy located in the direction of the constellation Eridanus. It was first discovered by astronomer John Herschel on November 5, 1837.
The galaxy is one of the prominent objects in astronomical research, particularly due to its central bar, spiral arms, star-forming regions, and active nucleus structure. NGC 1672 provides insight into the evolution of barred spiral galaxies due to both its morphological features and the astrophysical processes it hosts.
AI-Generated Image of NGC 1672
Basic Properties
- Name: NGC 1672
- Constellation: Eridanus
- Galaxy Type: SBb (Barred spiral galaxy)
- Surface Brightness: Approximately 11.5 magnitude
- Angular Dimensions: Approximately 6.6 × 5.5 arcminutes
- Distance: Approximately 60 million light-years (18 megaparsecs)
- Radial Velocity: Approximately 1325 km/s
- Redshift (z): 0.00446
The morphological classification of NGC 1672 has been made as SB(s)b according to the de Vaucouleurs system. This classification indicates that the galaxy has a distinct central bar structure and relatively loosely wound spiral arms.
Morphology and Structural Components
NGC 1672 features a prominent bar structure in its central region. This bar extends outward from the galaxy’s center and gives rise to the spiral arms. Bar structures can influence gas flows that guide star formation in galaxies and play a key role in feeding the active galactic nucleus (AGN) structures at the center.
The spiral arms are enriched with young, hot, blue stars and H II regions. These regions exhibit intense star formation activity. Additionally, in the outer parts of the galaxy, dust lanes and star clusters are scattered.
Star Formation and H II Regions
NGC 1672 is an actively star-forming galaxy. H II regions are densely observed especially along the spiral arms and at the ends of the bar. H II regions are emission regions formed by ionization of hydrogen gas around high-temperature young stars and are indicators of star formation rates in galaxies.
Multi-wavelength observations of this galaxy (optical, ultraviolet, infrared, and radio bands) have revealed that star formation is particularly concentrated at the ends of the bar, where gas accumulation increases. This supports the view that the bar structure directs gas away from the center and triggers star formation in the spiral arms.
Active Galactic Nucleus (AGN) and X-ray Emission
NGC 1672 hosts a low-level active galactic nucleus at its center. X-ray and radio observations indicate the presence of a supermassive black hole at the center. Investigations with the XMM-Newton and Chandra telescopes have shown that there is a low-luminosity AGN at the center of the galaxy and that the X-ray emission from this region originates from plasma structures surrounding the core.
Such low-luminosity AGNs (LLAGN) generally have low mass accretion rates and low ionization states. Although the nucleus of NGC 1672 is not as luminous as a typical Seyfert galaxy, it indicates that the central black hole is still active.
Multi-Wavelength Observations
NGC 1672 has been studied not only in the optical band but also in infrared and radio bands. Data from the Spitzer Space Telescope have revealed the dusty structures and star-forming regions of the galaxy in detail. Likewise, ultraviolet observations by GALEX have made significant contributions to determining the distribution of young star populations.
Radio band observations provide information about the magnetic field structures and supernova remnants within the galaxy. Observations support the existence of a regular magnetic field structure along the spiral arms.
Environmental Interactions and Evolutionary Status
NGC 1672 is not located within a large galaxy group; therefore, it is unlikely to have undergone major galactic collisions or mergers. However, the presence of the bar and the irregularities in the galaxy disk suggest that internal dynamic processes (such as bar instability) play an important role in the evolution of the galaxy.
The increase in star formation rate at the center of the galaxy and AGN activity can be explained by the bar enhancing the flow of matter into the central region. Such internal mechanisms can be as significant in galaxy evolution as external interactions.
NGC 1672. (NASA)
NGC 1672 is an important observational object in understanding the structural, morphological, and astrophysical properties of barred spiral galaxies.
Studied with high-resolution multi-wavelength observations, the galaxy sheds light on various research topics such as star formation, bar dynamics, and low-luminosity AGN activity. NGC 1672 also serves as a functional example in testing theoretical models on the effects of galactic bars on galaxy evolution.
