Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Matters Arising
  • Published:

Effects of density and temperature variations on the metallicity of Mrk 71

Nature Astronomy volume 8, pages 275–277 (2024)Cite this article

Subjects

arising from Y. Chen et al. Nature Astronomy https://doi.org/10.1038/s41550-023-01953-7 (2023)

Historically, two indicators of heavy element abundances in ionized nebulae—optical collisionally excited lines (CELs) with an exponential temperature (Te) dependence and recombination lines (RLs) with less Te sensitivity—have produced inconsistent results. By using the less Te-dependent infrared (IR) [O iii] CELs, Chen et al.1 argue that the temperature inhomogeneities scenario proposed by Peimbert2 cannot explain the abundance discrepancy in the star-forming galaxy Mrk 71. We show that this conclusion depends on several assumptions, mainly the absence of biases in electron density (ne) determinations, a parameter on which IR CELs depend more than optical CELs. Since multiple ne indicators in previous and the discussed work on Mrk 71 show important differences, we conclude that the existence of temperature inhomogeneities cannot be ruled out.

This is a preview of subscription content, access via your institution

Access options

Buy this article

  • Purchase on Springer Link
  • Instant access to full article PDF
Buy now

Prices may be subject to local taxes which are calculated during checkout

Fig. 1: Electron temperature versus electron density for different values of the reddening constant.

Data availability

All the data discussed here were presented by ref. 1.

Code availability

Our results use the PyNeb code, publicly available on GitHub: https://github.com/Morisset/PyNeb_devel.

References

  1. Chen, Y. et al. Accurate oxygen abundance of interstellar gas in Mrk 71 from optical and infrared spectra. Nat. Astron. 7, 771–778 (2023).

    Article  ADS  Google Scholar 

  2. Peimbert, M. Temperature determinations of H ii regions. Astrophys. J. 150, 825–834 (1967).

    Article  ADS  CAS  Google Scholar 

  3. Cardelli, J. A., Clayton, G. C. & Mathis, J. S. The relationship between infrared, optical, and ultraviolet extinction. Astrophys. J. 345, 245 (1989).

    Article  ADS  CAS  Google Scholar 

  4. Sutter, J. & Fadda, D. [C ii] map of the molecular ring and arms of the spiral galaxy NGC 7331. Astrophys. J. 926, 82 (2022).

    Article  ADS  Google Scholar 

  5. Fadda, D., Jacobson, J. D. & Appleton, P. N. Transient effects in Herschel/PACS spectroscopy. Astron. Astrophys. 594, A90 (2016).

    Article  ADS  Google Scholar 

  6. Luridiana, V., Morisset, C. & Shaw, R. A. PyNeb: a new tool for analyzing emission lines. I. Code description and validation of results. Astron. Astrophys. 573, A42 (2015).

    Article  ADS  Google Scholar 

  7. Gonzalez-Delgado, R. M. et al. Violent star formation in NGC 2363. Astrophys. J. 437, 239 (1994).

    Article  ADS  CAS  Google Scholar 

  8. Esteban, C., Peimbert, M., Torres-Peimbert, S. & Rodríguez, M. Optical recombination lines of heavy elements in giant extragalactic H ii regions. Astrophys. J. 581, 241–257 (2002).

    Article  ADS  CAS  Google Scholar 

  9. Esteban, C. et al. Keck HIRES spectroscopy of extragalactic H ii regions: C and O abundances from recombination lines. Astrophys. J. 700, 654–678 (2009).

    Article  ADS  CAS  Google Scholar 

  10. Mingozzi, M. et al. CLASSY IV. Exploring UV diagnostics of the interstellar medium in local high-z analogs at the dawn of the JWST era. Astrophys. J. 939, 110 (2022).

    Article  ADS  Google Scholar 

  11. García-Rojas, J. & Esteban, C. On the abundance discrepancy problem in H ii regions. Astrophys. J. 670, 457–470 (2007).

    Article  ADS  Google Scholar 

  12. Peimbert, A., Peña-Guerrero, M. A. & Peimbert, M. A classification of H ii regions based on oxygen and helium lines: the cases of TOL 2146-391 and TOL 0357-3915. Astrophys. J. 753, 39 (2012).

    Article  ADS  Google Scholar 

  13. Rubin, R. H. The effect of density variations on elemental abundance ratios in gaseous nebulae. Astrophys. J. Suppl. Ser. 69, 897 (1989).

    Article  ADS  CAS  Google Scholar 

  14. Méndez-Delgado, J. E., Esteban, C., García-Rojas, J., Kreckel, K. & Peimbert, M. Temperature inhomogeneities cause the abundance discrepancy in H ii regions. Nature 618, 249–251 (2023).

    Article  ADS  PubMed  Google Scholar 

  15. Méndez-Delgado, J. E. et al. Density biases and temperature relations for DESIRED H ii regions. Mon. Not. R. Astron. Soc. 523, 2952–2973 (2023).

    Article  ADS  Google Scholar 

Download references

Acknowledgements

J.E.M.-D. and K.K. gratefully acknowledge funding from the German Research Foundation in the form of an Emmy Noether Research Group (grant no. KR4598/2-1, PI Kreckel). K.K. additionally gratefully acknowledges funding from the European Research Council’s starting grant (grant no. ERC StG-101077573, ISM-METALS). C.E. and J.G.-R. acknowledge support from the Spanish Research Agency of the Ministry of Science, Innovation and Universities (MCIU) under grant Espectroscopía de campo integral de regiones H ii locales. Modelos para el estudio de regiones H ii extragalácticas (grant ref. 10.13039/501100011033) and support (grant no. P/308614), which is financed by the MCIU and charged to the General State Budgets and by the General Budgets of the Autonomous Community of the Canary Islands by the MCIU. J.G.-R. acknowledges support from an advanced fellowship under the Severo Ochoa excellence programme (ref. CEX2019-000920-S) and financial support from the Canarian Agency for Research, Innovation and Information Society of the Canary Islands Government and from the European Regional Development Fund (grant ref. ProID2021010074).

Author information

Authors and Affiliations

  1. Astronomisches Rechen-Institut, Zentrum für Astronomie der Universität Heidelberg, Heidelberg, Germany

    J. Eduardo Méndez-Delgado & Kathryn Kreckel

  2. Instituto de Astrofísica de Canarias (IAC), Santa Cruz de Tenerife, Spain

    César Esteban & Jorge García-Rojas

  3. Departamento de Astrofísica, Universidad de La Laguna, Santa Cruz de Tenerife, Spain

    César Esteban & Jorge García-Rojas

  4. Instituto de Astronomía, Universidad Nacional Autónoma de México, Mexico City, Mexico

    Manuel Peimbert

Authors
  1. J. Eduardo Méndez-Delgado
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. César Esteban
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Jorge García-Rojas
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. Kathryn Kreckel
    View author publications

    You can also search for this author in PubMed Google Scholar

  5. Manuel Peimbert
    View author publications

    You can also search for this author in PubMed Google Scholar

Contributions

J.E.M.-D. led the analysis and writing of the manuscript. C.E., J.G.-R., K.K. and M.P. provided critical feedback and modified the text.

Corresponding author

Correspondence to J. Eduardo Méndez-Delgado.

Ethics declarations

Competing interests

The authors declare no competing interests.

Peer review

Peer review information

Nature Astronomy thanks the anonymous reviewers for their contribution to the peer review of this work.

Additional information

Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Méndez-Delgado, J.E., Esteban, C., García-Rojas, J. et al. Effects of density and temperature variations on the metallicity of Mrk 71. Nat Astron 8, 275–277 (2024). https://doi.org/10.1038/s41550-024-02198-8

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/s41550-024-02198-8

This article is cited by

Search

Advanced search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing