Star Formation Rate of Galaxies in HCG7

Authors

  • Krishna Kumar Bhandari Central Department of Physics, Tribhuvan University, Kathmandu, Nepal
  • Daya Nidhi Chhatkuli Tri-Chandra Multiple Campus, Tribhuvan University, Kathmandu, Nepal https://orcid.org/0000-0002-8040-6902
  • Amrit Sedain Central Department of Physics, Tribhuvan University, Kathmandu, Nepal
  • Binil Aryal Central Department of Physics, Tribhuvan University, Kathmandu, Nepal https://orcid.org/0000-0002-1253-0741

DOI:

https://doi.org/10.3126/jist.v30i2.82819

Keywords:

Galaxy Merger, Hickson Compact Group, Metallicity, Star formation rate

Abstract

A small system of typically 4–10 galaxies that appear to be isolated from other galaxies and situated very close to one another on the sky leading to tidal distortions, gas stripping and star bursts is called a Hickson Compact Group (HCG). We present a spectroscopic analysis of four member galaxies of HCG 7: NGC 192, NGC 196, NGC 197, and NGC 201, using data from the Sloan Digital Sky Survey (SDSS) Data Releases 12. Emission lines in the galaxy spectra are modeled with Gaussian profiles, and the Hα line is used to estimate Star Formation Rates (SFRs) and gas-phase metallicities. After extinction correction, we derive SFRs of 0.284 M☉/year, 0.222 M☉/year, and 0.034 M☉/year for the star-forming galaxies, NGC 192, NGC 201, and NGC 197, respectively with corresponding gas-phase metallicities (12 + log(O/H)) of 8.64 dex, 8.55 dex, and 8.56 dex. In contrast, NGC 196 shows no detectable Hα emission, consistent with a quiescent spectrum. The absence of a significant star-forming interstellar medium in NGC 196 may be attributable to environmental processes, with tidal stripping being the most probable quenching mechanism in the dense HCG 7 environment.

Downloads

Download data is not yet available.
Abstract
0
PDF
0

References

Alam, S., Albareti, F. D., Allende Prieto, C., Anders, F., Anderson, S. F., Anderton, T., ... & York, D. G. (2015). The Eleventh and Twelfth Data Releases of the Sloan Digital Sky Survey: Final data from SDSS-III. The Astrophysical Journal Supplement Series, 219(1), 12. https://doi.org/10.1088/0067-0049/219/1/12.

Blom, C., Forbes, D. A., Foster, C. Romanowsky, A. J., & Brodie, J. P. (2014). The SLUGGS Survey: new evidence for a tidal interaction between the early-type galaxies NGC 4365 and NGC 4342, Monthly Notices of the Royal Astronomical Society, 439, 2420–2431.

Chhatkuli, D. N., Paudel, S., & Aryal, B. (2020). Study of Star Formation Rate and Metallicity of an Interacting Dwarf Galaxy NGC 2604. Journal of Institute of Science and Technology, 25(2), 55-60.

Chhatkuli, D. N., Paudel, S., Sedain, A., & Aryal, B. (2024). Dwarf galaxy merger-induced star formation rate: A case study of Mrk 1481. Bibechana, 21(2), 95-102.

Diaferio, A., Geller, M. J., & Ramella, M. (1994). The Formation of Compact Groups of Galaxies. I. Optical Properties. The Astronomical Journal, 107, 868-885.

Gallazzi, A., Charlot, S., Brinchmann, J., White, S. D. M., & Tremonti, C. A. (2005). The ages and metallicities of galaxies in the local universe. Monthly Notices of the Royal Astronomical Society, 362, 41-58.

Hickson, P. (1993). Atlas of Compact Groups of Galaxies. Astrophysical Letters and Communications, 29, 1.

Hickson, P. (1997). Compact groups of galaxies. Annual Review of Astronomy and Astrophysics, 35, 357-388.

Hickson, P., Oliveira C. M. D., C., Huchra, J. P., & Palumbo, G. G. (1992). Dynamical properties of compact groups of galaxies. The Astrophysical Journal, 399, 353-367.

Hickson, P. (1982). Systematic properties of compact groups of galaxies. The Astrophysical Journal, 255, 382-391. https://cseligman.com/tex/hickson.htm#hcg7.

Ianjamasimanana, R., Verdes-Montenegro, L., Sorgho, A., Hess, K. M., Jones, M. G., Cannon, J. M., ... & Smirnov, O. M. (2025). MeerKAT view of Hickson Compact Groups-I. Data description and release. Astronomy & Astrophysics, 696, A176.

Karttunen, H., Kröger, P., Poutanen, M., & Donner, K. J. (2007). Fundamental astronomy (5th ed.). Springer.

Kennicutt, R. C. (1998). Star formation in galaxies along the Hubble sequence. Annual Review of Astronomy and Astrophysics, 36, 189-232.

Martínez-Badénes, V., Lisenfeld, U., Espada, D., Verdes-Montenegro, L., García-Burillo, S., León, S., Sulentic, J., & Yun, M. S. (2012). Molecular gas content and star formation rate in Hickson Compact Groups: Enhanced or deficient? Astronomy & Astrophysics, 540, A96. https://doi.org/10.1051/0004-6361/201117281.

Oliveira, C. M. D., & Hickson, P. (1994). Morphology of Galaxies in Compact Groups. The Astrophysical Journal, 427, 684-695.

Ribeiro, A. L. B. and Carvalho, R. R. D., Capelato, H. V., & Zepf, S. E. (1998). Structural and dynamical analysis of the Hickson compact groups. The Astrophysical Journal, 497, 72-82.

Schmidt, M. (1959). The rate of star formation. The Astrophysical Journal, 129, 243. doi: 10.1086/146614.

Tzanavaris, P., Hornschemeier, A. E., Gallagher, S. C., Johnson, K. E., Gronwall, C., Immler, S., Reines, A. E., Hoversten, E., & Charlton, J. C. (2010). Ultraviolet+Infrared star formation rates: Hickson Compact Groups with Swift and Spitzer. The Astrophysical Journal, 716(1), 556-573. https://doi.org/10.1088/0004-637X/716/1/556.

Cover JIST

Downloads

Published

2025-12-23

How to Cite

Bhandari, K. K., Chhatkuli, D. N., Sedain, A., & Aryal, B. (2025). Star Formation Rate of Galaxies in HCG7 . Journal of Institute of Science and Technology, 30(2), 25–33. https://doi.org/10.3126/jist.v30i2.82819

Issue

Vol. 30 No. 2 (2025)

Section

Research Articles

License

Copyright (c) 2025 Institute of Science and Technology, T.U.

Creative Commons License

This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.

The views and interpretations in this journal are those of the author(s). They are not attributable to the Institute of Science and Technology, T.U. and do not imply the expression of any opinion concerning the legal status of any country, territory, city, area of its authorities, or concerning the delimitation of its frontiers of boundaries.

The copyright of the articles is held by the Institute of Science and Technology, T.U.