A three-dimensional map of the hot Local Bubble using diffuse interstellar bands

Abstract

The Solar System is located within a low-density cavity known as the Local Bubble1,2,3, which appears to be filled with an X-ray-emitting gas at a temperature of 106 K (ref. 4). Such conditions are too harsh for typical interstellar atoms and molecules to survive2,3. The diffuse interstellar bands (DIBs), the carriers of which remain largely unidentified5, often appear as absorption features in stellar spectra6,7,8 and can be used to trace interstellar gas. Here we report the three-dimensional (3D) structure of the Local Bubble using two different DIB tracers (λ5,780 and λ5,797), which reveals that DIB carriers are present within the Bubble9,10,11. The 3D map shows low values of λ5,797/λ5,780 inside the Bubble compared with the outside. This finding proves that the carrier of the λ5,780 DIB can withstand X-ray photodissociation and sputtering by fast ions, whereas the carrier of the λ5,797 DIB succumbs. This implies that DIB carriers are more stable than hitherto thought, and that the carrier of the λ5,780 DIB must be larger than that of the λ5,797 DIB12. Alternatively, small-scale denser (and cooler) structures that shield some of the DIB carriers must be prevalent within the Bubble, suggesting that such structures may be an intrinsic feature of supernova-driven bubbles.

Access options

Rent or Buy article

Get time limited or full article access on ReadCube.

from$8.99

All prices are NET prices.

Fig. 1: Observed DIB spectra within and around the LB.
Fig. 2: λ5,780 DIB distribution in three principal slices.
Fig. 3: ζ and σ cloud distribution within the GP.

Data availability

The data that support the plots within this paper and other findings of this study are available from the corresponding author on reasonable request.

References

  1. 1.

    Cox, D. P. & Reynolds, R. J. The local interstellar medium. Annu. Rev. Astron. Astrophys. 25, 303–344 (1987).

    ADS  Article  Google Scholar 

  2. 2.

    Welsh, B. Y., Lallement, R., Vergely, J.-L. & Raimond, S. New 3D gas density maps of NaI and CaII interstellar absorption within 300 pc. Astron. Astrophys. 510, A54 (2010).

    ADS  Article  Google Scholar 

  3. 3.

    Lallement, R. et al. 3D maps of the local ISM from inversion of individual color excess measurements. Astron. Astrophys. 561, A91 (2014).

    Article  Google Scholar 

  4. 4.

    Galeazzi, M. et al. The origin of the local 1/4-keV X-ray flux in both charge exchange and a hot bubble. Nature 512, 171–173 (2014).

    ADS  Article  Google Scholar 

  5. 5.

    Sarre, P. J. The diffuse interstellar bands: a major problem in astronomical spectroscopy. J. Mol. Spectrosc. 238, 1–10 (2006).

    ADS  Article  Google Scholar 

  6. 6.

    Heckman, T. M. & Lehnert, M. D. The detection of the diffuse interstellar bands in dusty starburst galaxies. Astrophys. J. 537, 690–696 (2000).

    ADS  Article  Google Scholar 

  7. 7.

    Phillips, M. M. et al. On the source of the dust extinction in type Ia supernovae and the discovery of anomalously strong Na I absorption. Astrophys. J. 779, 38 (2013).

    ADS  Article  Google Scholar 

  8. 8.

    Monreal-Ibero, A. et al. Towards DIB mapping in galaxies beyond 100 Mpc. A radial profile of the λ5780.5 diffuse interstellar band in AM 1353-272 B. Astron. Astrophys. 576, L3 (2015).

    ADS  Article  Google Scholar 

  9. 9.

    Bailey, M. et al. Probing the Local Bubble with diffuse interstellar bands. I. Project overview and southern hemisphere survey. Astron. Astrophys. 585, A12 (2016).

    Article  Google Scholar 

  10. 10.

    Farhang, A. et al. Probing the Local Bubble with diffuse interstellar bands. II. The DIB properties in the northern hemisphere. Astrophys. J. 800, 64 (2015).

    ADS  Article  Google Scholar 

  11. 11.

    Farhang, A., Khosroshahi, H. G., Javadi, A. & van Loon, J. T. Probing the Local Bubble with diffuse interstellar bands. III. The northern hemisphere data and catalog. Astrophys. J. Suppl. 216, 33 (2015).

    ADS  Article  Google Scholar 

  12. 12.

    Micelotta, E. R., Jones, A. P. & Tielens, A. G. G. M. Polycyclic aromatic hydrocarbon processing in a hot gas. Astron. Astrophys. 510, A37 (2010).

    ADS  Article  Google Scholar 

  13. 13.

    Fuchs, B., Breitschwerdt, D., de Avillez, M. A., Dettbarn, C. & Flynn, C. The search for the origin of the Local Bubble redivivus. Mon. Not. R. Astron. Soc. 373, 993–1003 (2006).

    ADS  Article  Google Scholar 

  14. 14.

    Holberg, J. B., Barstow, M. A., Bruhweiler, F. C., Hubeny, I. & Green, E. M. Far-ultraviolet space telescope imaging spectrometer spectra of the white dwarf REJ 1032+532. II. Stellar spectrum. Astrophys. J. 517, 850–858 (1999).

    ADS  Article  Google Scholar 

  15. 15.

    Fulara, J., Jakobi, M. & Maier, J. P. Electronic and infrared spectra of C+ 60 and C 60 in neon and argon matrices. Chem. Phys. Lett. 211, 227–234 (1993).

    ADS  Article  Google Scholar 

  16. 16.

    Sneden, C., Woszczyk, A. & Krelowski, J. Diffuse-band observations related to the interstellar extinction law. Publ. Astron. Soc. Pac. 103, 1005 (1991).

    ADS  Article  Google Scholar 

  17. 17.

    Vos, D. A. I., Cox, N. L. J., Kaper, L., Spaans, M. & Ehrenfreund, P. Diffuse interstellar bands in Upper Scorpius: probing variations in the DIB spectrum due to changing environmental conditions. Astron. Astrophys. 533, A129 (2011).

    ADS  Article  Google Scholar 

  18. 18.

    Capitanio, L., Lallement, R., Vergely, J. L., Elyajouri, M. & Monreal-Ibero, A. Three-dimensional mapping of the local interstellar medium with composite data. Astron. Astrophys. 606, A65 (2017).

    ADS  Article  Google Scholar 

  19. 19.

    Lallement, R. et al. Gaia-2MASS 3D maps of Galactic interstellar dust within 3 kpc. Preprint at https://arxiv.org/pdf/1902.04116.pdf (2019).

  20. 20.

    Kos, J. et al. Pseudo-three-dimensional maps of the diffuse interstellar band at 862 nm. Science 345, 791–795 (2014).

    ADS  Article  Google Scholar 

  21. 21.

    Cox, N. L. J., Kaper, L., Foing, B. H. & Ehrenfreund, P. Diffuse interstellar bands of unprecedented strength in the line of sight towards high-mass X-ray binary 4U 1907+09. Astron. Astrophys. 438, 187–199 (2005).

    ADS  Article  Google Scholar 

  22. 22.

    Welsh, B. Y., Sfeir, D. M., Sirk, M. M. & Lallement, R. EUV mapping of the local interstellar medium: the Local Chimney revealed? Astron. Astrophys. 352, 308–316 (1999).

    ADS  Google Scholar 

  23. 23.

    Puspitarini, L. & Lallement, R. Distance to northern high-latitude HI shells. Astron. Astrophys. 545, A21 (2012).

    ADS  Article  Google Scholar 

  24. 24.

    Weilbacher, P. M. et al. A MUSE map of the central Orion Nebula (M 42). Astron. Astrophys. 582, A114 (2015).

    Article  Google Scholar 

  25. 25.

    Ranalli, P., Comastri, A., Origlia, L. & Maiolino, R. A deep X-ray observation of M82 with XMM-Newton. Mon. Not. R. Astron. Soc. 386, 1464–1480 (2008).

    ADS  Article  Google Scholar 

  26. 26.

    Micelotta, E. R. et al. The formation of cosmic fullerenes from arophatic clusters. Astrophys. J. 761, 35 (2012).

    ADS  Article  Google Scholar 

  27. 27.

    Breitschwerdt, D. & de Avillez, M. A. The history and future of the local and loop I bubbles. Astron. Astrophys. 452, L1–L5 (2006).

    ADS  Article  Google Scholar 

  28. 28.

    Pittard, J. M. Self-sealing shells: blowouts and blisters on the surfaces of leaky wind-blown bubbles and supernova remnants. Mon. Not. R. Astron. Soc. 435, 3600–3613 (2013).

    ADS  Article  Google Scholar 

  29. 29.

    Gatto, A. et al. Modelling the supernova-driven ISM in different environments. Mon. Not. R. Astron. Soc. 449, 1057–1075 (2015).

    ADS  Article  Google Scholar 

  30. 30.

    Wallner, A. et al. Recent near-Earth supernovae probed by global deposition of interstellar radioactive 60Fe. Nature 532, 69–72 (2016).

    ADS  Article  Google Scholar 

  31. 31.

    van Loon, J. T. et al. Detailed maps of interstellar clouds in front of ω Centauri: small-scale structures in the Galactic disc-halo interface. Mon. Not. R. Astron. Soc. 399, 195–208 (2009).

    ADS  Article  Google Scholar 

  32. 32.

    Herbig, G. H. The diffuse interstellar bands. IV—The region 4400-6850 A. Astrophys. J. 196, 129–160 (1975).

    ADS  Article  Google Scholar 

  33. 33.

    Kos, J. & Zwitter, T. Properties of diffuse interstellar bands at different physical conditions of the interstellar medium. Astrophys. J. 774, 72 (2013).

    ADS  Article  Google Scholar 

  34. 34.

    Gaia Collaboration et al. Gaia data release 2. Observational Hertzsprung-Russell diagrams. Astron. Astrophys. 616, A10 (2018).

    Article  Google Scholar 

  35. 35.

    Gaia Collaboration et al. Gaia data release 2. Summary of the contents and survey properties. Astron. Astrophys. 616, A1 (2018).

    Article  Google Scholar 

  36. 36.

    Bailer-Jones, C. A. L., Rybizki, J., Fouesneau, M., Mantelet, G. & Andrae, R. Estimating distance from parallaxes. IV. Distances to 1.33 billion stars in Gaia data release 2. Astron. J. 156, 58 (2018).

    ADS  Article  Google Scholar 

  37. 37.

    Tarantola, A. & Valette, B. Generalized nonlinear inverse problems solved using the least squares criterion (Paper 1R1855). Rev. Geophys. Space Phys. 20, 219 (1982).

    ADS  MathSciNet  Article  Google Scholar 

  38. 38.

    Tarantola, A. & Nercessian, A. Three-dimensional inversion without blocks. Geophys. J. 76, 299–306 (1984).

    ADS  Article  Google Scholar 

Download references

Acknowledgements

We wish to thank the Iranian National Observatory and School of Astronomy at IPM for facilitating and supporting this project for the northern part of the observations, and Keele University for their hospitality during the visits of A.F. and A.J. and for their support of the southern observations. Also, we wish to thank all of the staff at La Silla in Chile and the ING staff at La Palma, Spain—scientific, technical and administration—for their assistance. M.B. acknowledges an STFC studentship at Keele University. This research has made use of the SIMBAD database, operated at CDS Strasbourg, France. A.F. would like to thank J. Cami for his comments on the paper.

Author information

Affiliations

Authors

Contributions

The main idea for this work was proposed by J.T.v.L. and M.B. The northern observations (with the INT) were proposed by A.J. and carried out by A.F. and H.G.K. as well as other colleagues within the School of Astronomy at IPM, while M.B. and J.T.v.L. proposed and observed the southern targets (with the NTT). A.F. performed the data analysis and data reduction of the northern observations, while M.B. did the same for the southern sample. A.F. implemented the inverse method on the combined data set, and together with J.T.v.L. and H.G.K. wrote the manuscript. All authors read and commented on the manuscript and contributed to the scientific interpretation.

Corresponding author

Correspondence to Amin Farhang.

Ethics declarations

Competing interests

The authors declare no competing interests.

Additional information

Peer review information: Nature Astronomy thanks Lucky Puspitarini, Barry Welsh and the other, anonymous, reviewer(s) for their contribution to the peer review of this work.

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

Supplementary information

41550_2019_814_MOESM2_ESM.mp4

The 3D distribution of the λ5,780 DIB within 200 pc of the Sun. Colours represent the logarithm of volume density of the λ5,780 DIB. The Sun is located at the centre of the map. In this movie, the x axis gives the direction toward the GC and the z axis indicates the direction toward the NGP, perpendicular to the GP. All distances in this animation are in parsecs.

Supplementary Information

Supplementary Video 1 caption, Supplementary Figs. 1–6, Supplementary text and Supplementary refs.

Supplementary Video 1

The 3D distribution of the λ5,780 DIB within 200 pc of the Sun. Colours represent the logarithm of volume density of the λ5,780 DIB. The Sun is located at the centre of the map. In this movie, the x axis gives the direction toward the GC and the z axis indicates the direction toward the NGP, perpendicular to the GP. All distances in this animation are in parsecs.

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Farhang, A., van Loon, J.T., Khosroshahi, H.G. et al. A three-dimensional map of the hot Local Bubble using diffuse interstellar bands. Nat Astron 3, 922–927 (2019). https://doi.org/10.1038/s41550-019-0814-z

Download citation

Further reading