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Cold gas outflows from the Small Magellanic Cloud traced with ASKAP


Feedback from massive stars plays a critical part in the evolution of the Universe by driving powerful outflows from galaxies that enrich the intergalactic medium and regulate star formation1. An important source of outflows may be the most numerous galaxies in the Universe: dwarf galaxies. With small gravitational potential wells, these galaxies easily lose their star-forming material in the presence of intense stellar feedback1,2. Here, we show that a nearby dwarf galaxy—the Small Magellanic Cloud—has atomic hydrogen outflows extending at least 2 kiloparsecs from the star-forming bar of the galaxy. The outflows are cold (< 400 K) and may have formed during a period of active star formation 25–60 Myr ago3,4. The total mass of atomic gas in the outflow is about 107 solar masses (that is, about 3 per cent of the total atomic gas of the galaxy). The inferred mass flux in atomic gas alone, \(\dot M_{{\mathrm{H}}\;{\textsc{{I}}}}\)  ≈ 0.2–1.0 solar masses per year, is up to one order of magnitude greater than the star-formation rate. We suggest that most of the observed outflow will be stripped from the Small Magellanic Cloud through its interaction with its companion, the Large Magellanic Cloud, and the Milky Way, feeding the Magellanic Stream of hydrogen encircling the Milky Way.

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Fig. 1: Peak H i brightness temperature intensity of the SMC from ASKAP and Parkes.
Fig. 2: Three-colour images of H i emission for four velocity ranges.
Fig. 3: SMC Hα emission from the MCELS survey.
Fig. 4: Mean H i spectrum for the region to the north-west of the bar, displayed as a function of vLSR.

Data availability

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


  1. Hopkins, P. F., Quataert, E. & Murray, N. Stellar feedback in galaxies and the origin of galaxy-scale winds. Mon. Not. R. Astron. Soc. 421, 3522–3537 (2012).

    Article  ADS  Google Scholar 

  2. Ferrara, A. & Tolstoy, E. The role of stellar feedback and dark matter in the evolution of dwarf galaxies. Mon. Not. R. Astron. Soc. 313, 291–309 (2000).

    Article  ADS  Google Scholar 

  3. Rubele, S. et al. The VMC survey—XIV. First results on the look-back time star formation rate tomography of the Small Magellanic Cloud. Mon. Not. R. Astron. Soc. 449, 639–661 (2015).

    Article  ADS  Google Scholar 

  4. Hagen, L. M. Z. et al. Swift ultraviolet survey of the magellanic clouds (SUMaC)—I. Shape of the ultraviolet dust extinction law and recent star formation history of the Small Magellanic Cloud. Mon. Not. R. Astron. Soc. 466, 4540–4557 (2017).

    ADS  Google Scholar 

  5. Jacyszyn-Dobrzeniecka, A. M. et al. OGLE-ing the Magellanic system: three-dimensional structure of the clouds and the bridge using classical Cepheids. Acta Astronom. 66, 149–196 (2016).

    ADS  Google Scholar 

  6. Bolatto, A. D. et al. The Spitzer survey of the Small Magellanic Cloud: S3MC imaging and photometry in the mid- and far-infrared wave bands. Astrophys. J. 655, 212–232 (2007).

    Article  ADS  Google Scholar 

  7. Stanimirović, S., Staveley-Smith, L. & Jones, P. A. A new look at the kinematics of neutral hydrogen in the Small Magellanic Cloud. Astrophys. J. 604, 176–186 (2004).

    Article  ADS  Google Scholar 

  8. McClure-Griffiths, N. M. et al. Evidence for chimney breakout in the galactic supershell GSH 242-03+37. Astrophys. J. 638, 196–205 (2006).

    Article  ADS  Google Scholar 

  9. Pidopryhora, Y., Lockman, F. J. & Shields, J. C. The Ophiuchus superbubble: a gigantic eruption from the inner disk of the Milky Way. Astrophys. J. 656, 928–942 (2007).

    Article  ADS  Google Scholar 

  10. Howk, J. C. & Savage, B. D. Extraplanar dust in the edge-on spiral NGC 891. Astron. J. 114, 2463–2478 (1997).

    Article  ADS  Google Scholar 

  11. Howk, J. C. & Savage, B. D. The multiphase halo of NGC 891: WIYN Hα and BVI imaging. Astron. J. 119, 644–667 (2000).

    Article  ADS  Google Scholar 

  12. Lockman, F. J., Benjamin, R. A., Heroux, A. J. & Langston, G. I. The Smith cloud: a high-velocity cloud colliding with the milky way. Astrophys. J. 679, L21–L24 (2008).

    Article  ADS  Google Scholar 

  13. Smith, R. & MCELS Team. The UM/CTIO Magellanic Cloud Emission-line Survey. In New Views of the Magellanic Clouds (eds Chu, Y.-H., Suntzeff, N., Hesser, J. & Bohlender, D.) 28 (Conference Series Volume 190, IAU Symposium, 1999).

  14. Winkler, P. F., Smith, R. C., Points, S. D. & MCELS Team. The interstellar medium in the Small Magellanic Cloud: results from MCELS. In Fifty Years of Wide Field Studies in the Southern Hemisphere: Resolved Stellar Populations of the Galactic Bulge and Magellanic Clouds (eds Points, S. & Kunder, A.) 343 (Conference Series Volume 491, Astronomical Society of the Pacific, 2015).

  15. Staveley-Smith, L., Sault, R. J., Hatzidimitriou, D., Kesteven, M. J. & McConnell, D. An H i aperture synthesis mosaic of the Small Magellanic Cloud. Mon. Not. R. Astron. Soc. 289, 225–252 (1997).

    Article  ADS  Google Scholar 

  16. Brüns, C. et al. The Parkes H i survey of the magellanic system. Astron. Astrophys. 432, 45–67 (2005).

    Article  ADS  Google Scholar 

  17. Hatzidimitriou, D. et al. On the properties of H i shells in the Small Magellanic Cloud. Mon. Not. R. Astron. Soc. 360, 1171–1184 (2005).

    Article  ADS  Google Scholar 

  18. D’Onghia, E. & Fox, A. J. The Magellanic stream: circumnavigating the galaxy. Ann. Rev. Astron. Astrophys. 54, 363–400 (2016).

    Article  ADS  Google Scholar 

  19. Kallivayalil, N. et al. The proper motion of the Large Magellanic Cloud using HST. Astrophys. J. 638, 772–785 (2006).

    Article  ADS  Google Scholar 

  20. Kallivayalil, N., van der Marel, R. P. & Alcock, C. Is the SMC bound to the LMC? The Hubble Space Telescope proper motion of the SMC. Astrophys. J. 652, 1213–1229 (2006).

    Article  ADS  Google Scholar 

  21. Besla, G. et al. Are the magellanic clouds on their first passage about the Milky Way? Astrophys. J. 668, 949–967 (2007).

    Article  ADS  Google Scholar 

  22. Gardiner, L. T. & Noguchi, M. N-body simulations of the Small Magellanic Cloud and the magellanic stream. Mon. Not. R. Astron. Soc. 278, 191–208 (1996).

    Article  ADS  Google Scholar 

  23. Carrera, R., Conn, B. C., Noël, N. E. D. & Read, J. I., . & López Sánchez, Á. R. The Magellanic Inter-Cloud Project (MAGIC) III: first spectroscopic evidence of a dwarf stripping a dwarf. Mon. Not. R. Astron. Soc. 471, 4571–4578 (2017).

    Article  ADS  Google Scholar 

  24. Besla, G. et al. The role of dwarf galaxy interactions in shaping the Magellanic system and implications for Magellanic irregulars. Mon. Not. R. Astron. Soc. 421, 2109–2138 (2012).

    Article  ADS  Google Scholar 

  25. Hammer, F., Yang, Y. B., Flores, H., Puech, M. & Fouquet, S. The Magellanic stream system. I. Ram-pressure tails and the relics of the collision between the Magellanic clouds. Astrophys. J. 813, 110 (2015).

    Article  ADS  Google Scholar 

  26. Sturm, R. & Haberl, F. The diffuse X-ray emission of the Small Magellanic Cloud. In Proc. The X-ray Universe 2014 191 (Max-Planck-Institut für extraterrestrische Physik, 2014);

  27. Hoopes, C. G., Sembach, K. R., Howk, J. C., Savage, B. D. & Fullerton, A. W. A far ultraviolet spectroscopic explorer survey of interstellar O vi absorption in the Small Magellanic Cloud. Astrophys. J. 569, 233–244 (2002).

    Article  ADS  Google Scholar 

  28. DeBoer, D. R. et al. Australian SKA Pathfinder: a high-dynamic range wide-field of view survey telescope. IEEE Proc. 97, 1507–1521 (2009).

    Article  ADS  Google Scholar 

  29. McConnell, D. et al. The Australian Square Kilometre Array Pathfinder: performance of the Boolardy Engineering Test Array. Publ. Astron. Soc. Aus. 33, e042 (2016).

    Article  ADS  Google Scholar 

  30. Hotan, A. W. et al. The Australian Square Kilometre Array Pathfinder: system architecture and specifications of the Boolardy Engineering Test Array. Publ. Astron. Soc. Aus. 31, e041 (2014).

    Article  ADS  Google Scholar 

  31. McConnell, D. ACES Memo 15: Observing with ASKAP: Optimisation for Survey Speed Technical report (CSIRO Australia Telescope National Facility, 2017);

  32. Ekers, R. D. & Rots, A. H. Short spacing synthesis from a primary beam scanned interferometer. In Proc. IAU Colloquium (eds van Schooneveld, C. & Reidel, D.) Vol. 76, 61–66 (Astrophysics and Space Science Library, 1979).

  33. Cornwell, T. J., Humphreys, B., Lenc, E., Voronkov, M. & Whiting, M. T. ASKAP Science Processing: Askap-sw-0020 Technical report 028 (ASKAP Science Case Memo Series, CSIRO, 2011);

  34. Sault, R. J., Staveley-Smith, L. & Brouw, W. N. An approach to interferometric mosaicing. Astron. Astrophys. Suppl. Ser. 120, 375–384 (1996).

    Article  ADS  Google Scholar 

  35. Stanimirović, S., Staveley-Smith, L., Dickey, J. M., Sault, R. J. & Snowden, S. L. The large-scale H i structure of the Small Magellanic Cloud. Mon. Not. R. Astron. Soc. 302, 417–436 (1999).

    Article  ADS  Google Scholar 

  36. HI4PI Collaboration et al. HI4PI: a full-sky H i survey based on EBHIS and GASS. Astron. Astrophys. 594, A116 (2016).

    Article  Google Scholar 

  37. The Astropy Collaboration et al. The Astropy Project: building an inclusive, open-science project and status of the v2.0 core package. Preprint at (2018).

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ASKAP is part of the Australia Telescope National Facility, which is managed by CSIRO. Operation of the ASKAP is funded by the Australian Government with support from the National Collaborative Research Infrastructure Strategy. The ASKAP uses the resources of the Pawsey Supercomputing Centre. The ASKAP, Murchison Radio-astronomy Observatory and Pawsey Supercomputing Centre were established as initiatives of the Australian Government, with support from the Government of Western Australia and Science and Industry Endowment Fund. We acknowledge the Wajarri Yamatji people as the traditional owners of the observatory site. The MCELS data were provided by R. C. Smith, P. F. Winkler and S. D. Points. The MCELS project has been supported in part by NSF grants AST-9540747 and AST-0307613, and through the generous support of the Dean B. McLaughlin Fund at the University of Michigan—a bequest from the family of D. B. McLaughlin in memory of his lasting impact on astronomy. Parts of this research were conducted by the Australian Research Council Centre of Excellence for All Sky Astrophysics in 3 Dimensions, through project number CE170100013. N.M.M.-G. acknowledges funding from the Australian Research Council via grant FT150100024. We gratefully acknowledge contributions by W. Raja and K. Bannister to ASKAP commissioning.

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Authors and Affiliations



N.M.M.-G., J.M.D., S.S. and L.S.-S. developed the idea for the project. H.D. calibrated the ASKAP data. N.M.M.-G. and H.D. produced the ASKAP plus Parkes H i data cube. J.R.A., J.D.C, A.P.C., T.F, G.H, A.H., D.K., K.L.-W., D.M., A.P., J.R., C.J.R., M.A.V. and M.W. are members of the ASKAP Early Science and Commissioning team, with responsibility for delivery of ASKAP data. N.M.M.-G. wrote the paper with direct contributions from H.D., J.M.D., S.S., L.S.-S., K.J. and E.D.T. All authors reviewed the manuscript.

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Correspondence to N. M. McClure-Griffiths.

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McClure-Griffiths, N.M., Dénes, H., Dickey, J.M. et al. Cold gas outflows from the Small Magellanic Cloud traced with ASKAP. Nat Astron 2, 901–906 (2018).

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