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.

  • Letter
  • Published:

Episodic molecular outflow in the very young protostellar cluster Serpens South

Abstract

The loss of mass from protostars, in the form of a jet or outflow, is a necessary counterpart to protostellar mass accretion1,2. Outflow ejection events probably vary in their velocity and/or in the rate of mass loss. Such ‘episodic’ ejection events3 have been observed during the class 0 protostellar phase (the early accretion stage)4,5,6,7,8,9,10, and continue during the subsequent class I phase that marks the first one million years of star formation11,12,13,14. Previously observed episodic-ejection sources were relatively isolated; however, the most common sites of star formation are clusters15. Outflows link protostars with their environment and provide a viable source of the turbulence that is necessary for regulating star formation in clusters3, but it is not known how an accretion-driven jet or outflow in a clustered environment manifests itself in its earliest stage. This early stage is important in establishing the initial conditions for momentum and energy transfer to the environment as the protostar and cluster evolve. Here we report that an outflow from a young, class 0 protostar, at the hub of the very active and filamentary Serpens South protostellar cluster16,17,18, shows unambiguous episodic events. The 12C16O (J = 2−1) emission from the protostar reveals 22 distinct features of outflow ejecta, the most recent having the highest velocity. The outflow forms bipolar lobes—one of the first detectable signs of star formation—which originate from the peak of 1-mm continuum emission. Emission from the surrounding C18O envelope shows kinematics consistent with rotation and an infall of material onto the protostar. The data suggest that episodic, accretion-driven outflow begins in the earliest phase of protostellar evolution, and that the outflow remains intact in a very clustered environment, probably providing efficient momentum transfer for driving turbulence.

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

Access options

Buy this article

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

Figure 1: 12CO molecular outflow emission centered at the class 0 protostar CARMA-7 (C7).
Figure 2: Outflow ejecta from C7.
Figure 3: Protostellar envelope.

Similar content being viewed by others

References

  1. Norman, C. & Silk, J. Clumpy molecular clouds—a dynamic model self-consistently regulated by T Tauri star formation. Astrophys. J. 238, 158–174 (1980)

    Article  ADS  CAS  Google Scholar 

  2. Shu, F. H., Adams, F. C. & Lizano, S. Star formation in molecular clouds—observation and theory. Annu. Rev. Astron. Astrophys. 25, 23–81 (1987)

    Article  ADS  CAS  Google Scholar 

  3. Frank, A. et al. in Protostars and Planets VI (eds Beuther, H. et al. ) 451–474 (Univ. Arizona, 2014)

  4. Gueth, F. & Guilloteau, S. The jet-driven molecular outflow of HH 211. Astrophys. J. 343, 571–584 (1999)

    ADS  CAS  Google Scholar 

  5. Lee, C.-F., Mundy, L. G., Reipurth, B., Ostriker, E. C. & Stone, J. M. CO outflows from young stars: confronting the jet and wind models. Astrophys. J. 542, 925–945 (2000)

    Article  ADS  CAS  Google Scholar 

  6. Lee, C.-F. et al. HH 212: submillimeter array observations of a remarkable protostellar jet. Astrophys. J. 659, 499–511 (2007)

    Article  ADS  CAS  Google Scholar 

  7. Lee, C.-F. et al. Submillimeter arcsecond-resolution mapping of the highly collimated protostellar jet HH 211. Astrophys. J. 670, 1188–1197 (2007)

    Article  ADS  CAS  Google Scholar 

  8. Santiago-Garcia, J., Tafalla, M., Johnstone, D. & Bachiller, R. Shells, jets, and internal working surfaces in the molecular outflow from IRAS 04166+2706. Astrophys. J. 495, 169–181 (2009)

    ADS  CAS  Google Scholar 

  9. Hirano, N. et al. Extreme active molecular jets in L1448C. Astrophys. J. 717, 58–73 (2010)

    Article  ADS  CAS  Google Scholar 

  10. Loinard, L. et al. ALMA and VLA observations of the outflows in IRAS 16293–2422. Mon. Not. R. Astron. Soc. 430, L10–L14 (2013)

    Article  ADS  CAS  Google Scholar 

  11. Cabrit, S. & Raga, A. Theoretical interpretation of the apparent deceleration in the HH 34 superjet. Astrophys. J. 354, 667–673 (2000)

    ADS  Google Scholar 

  12. Goodman, A. A. & Arce, H. G. PV Cephei: young star caught speeding? Astrophys. J. 608, 831–845 (2004)

    Article  ADS  Google Scholar 

  13. Ioannidis, G. & Froebrich, D. YSO jets in the galactic plane from UWISH2—II. Outflow luminosity and length distributions in Serpens and Aquila. Mon. Not. R. Astron. Soc. 425, 1380–1393 (2012)

    Article  ADS  CAS  Google Scholar 

  14. Arce, H. G. et al. ALMA observations of the HH 46/47 molecular outflow. Astrophys. J. 774, 39 (2013)

    Article  ADS  CAS  Google Scholar 

  15. Lada, C.-J. & Lada, E. A. Embedded clusters in molecular clouds. Mon. Not. R. Astron. Soc. 41, 57–115 (2003)

    ADS  Google Scholar 

  16. Gutermuth, R. A. et al. The Spitzer Gould belt survey of large nearby interstellar clouds: discovery of a dense embedded cluster in the Serpens-Aquila Rift. Astrophys. J. 673, L151–L154 (2008)

    Article  ADS  CAS  Google Scholar 

  17. Tanaka, T. et al. The dynamical state of the Serpens South filamentary infrared dark cloud. Astrophys. J. 778, 34 (2013)

    Article  ADS  Google Scholar 

  18. Nakamura, F. et al. Cluster formation triggered by filament collisions in Serpens South. Astrophys. J. 791, L23 (2014)

    Article  ADS  Google Scholar 

  19. Dzib, S. et al. VLBA determination of the distance to nearby star-forming regions. IV. A preliminary distance to the proto-Herbig AeBe star EC 95 in the Serpens core. Astrophys. J. 718, 610–619 (2010)

    Article  ADS  Google Scholar 

  20. Kirk, H. et al. Filamentary accretion flows in the embedded Serpens South protocluster. Astrophys. J. 766, 115–128 (2013)

    Article  ADS  Google Scholar 

  21. Plunkett, A. L. et al. Assessing molecular outflows and turbulence in the protostellar cluster Serpens South. Astrophys. J. 803, 22 (2015)

    Article  ADS  Google Scholar 

  22. Nakamura, F. et al. Molecular outflows from the protocluster Serpens South. Astrophys. J. 737, 56 (2011)

    Article  ADS  Google Scholar 

  23. Raga, A. C., Binette, L., Canto, J. & Calvet, N. Stellar jets with intrinsically variable sources. Astrophys. J. 364, 601–610 (1990)

    Article  ADS  Google Scholar 

  24. Suttner, G., Smith, M. D., Yorke, H. W. & Zinnecker, H. Multi-dimensional numerical simulations of molecular jets. Astron. Astrophys. 318, 595–607 (1997)

    ADS  Google Scholar 

  25. Smith, M. D., Suttner, G. & Yorke, H. W. Numerical hydrodynamic simulations of jet-driven bipolar outflows. Astron. Astrophys. 323, 223–230 (1997)

    ADS  Google Scholar 

  26. Audard, M. et al. in Protostars and Planets VI (eds Beuther, H. et al. ) 387–410 (Univ. Arizona, 2014)

  27. Raga, A. C., Velázquez, P. F., Cantó, J. & Masciadri, E. The time-dependent ejection velocity histories of HH 34 and HH 111. Astrophys. J. 395, 647–656 (2002)

    ADS  Google Scholar 

  28. Teixeira, G. D. C., Kumar, M. S. N., Bachiller, R. & Grave, J. M. C. Molecular hydrogen jets and outflows in the Serpens South filamentary cloud. Astrophys. J. 543, A51 (2012)

    Google Scholar 

  29. Oya, Y. et al. A substellar-mass protostar and its outflow of IRAS 15398–3359 revealed by subarcsecond-resolution observations of H2CO and CCH. Astrophys. J. 795, 152 (2014)

    Article  ADS  Google Scholar 

  30. Lee, C.-F. et al. ALMA results of the pseudodisk, rotating disk, and jet in the continuum and HCO+ in the protostellar system HH 212. Astrophys. J. 786, 114 (2014)

    Article  ADS  Google Scholar 

Download references

Acknowledgements

A.L.P. is supported by a National Science Foundation (NSF) Graduate Research Fellowship under grant DGE-1122492; this research was made possible by the US Student Program of Fulbright Chile. H.G.A. receives funding from the NSF under grant AST-0845619. D.M. acknowledges support from CONICYT project PFB-06. M.M.D. acknowledges support from the Submillimeter Array through a postdoctoral fellowship. ALMA is a partnership of the European Space Organization (ESO, representing its member states), NSF (USA) and National Institutes of Natural Sciences (Japan), together with the National Research Council (Canada) and National Security Council and Academia Sinica Institute of Astronomy and Astrophysics (Taiwan), in cooperation with the Republic of Chile. The Joint ALMA Observatory is operated by ESO, Associated Universities Inc. (AUI)/National Radio Astronomy Observatory (NRAO) and National Astronomical Observatory of Japan. The NRAO is a facility of the NSF, operated under cooperative agreement by AUI. This paper makes use of the following ALMA data: ADS/JAO.ALMA 2012.1.00769.S.

Author information

Authors and Affiliations

Authors

Contributions

A.L.P. led the proposal, observations, analysis and interpretation, and wrote the manuscript. H.G.A. contributed to the analysis and interpretation, and to the manuscript. A.L.P., H.G.A., D.M., M.M.D., J.G. and S.A.C. planned the early stages of the project. D.M., M.M.D., M.F.-L. and J.G. contributed to the analysis and interpretation and commented on the manuscript. P.v.D. contributed to the interpretation and to the manuscript.

Corresponding authors

Correspondence to Adele L. Plunkett or Héctor G. Arce.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Extended data figures and tables

Extended Data Figure 1 C18O emission from the protostellar source C7.

Top row, blueshifted emission; bottom row, redshifted emission; velocity increases from left to right. Contours begin at 4σ and increment by 4σ. Specific velocity ranges (|VLSR − Vc|, or velocity relative to cloud velocity) are given for each column. Each panel shows integrated emission from two channels. The location of peak continuum emission is marked with a magenta cross.

Extended Data Figure 2 1-mm continuum emission near the sources CARMA-7 (RA = 18 h 30 min 04.1 s, dec. = −02° 03′ 02.6″) and CARMA-6 (RA = 18 h 30 min 03.5 s, dec. = −02° 03′ 08.4″).

Contours show 10σ, 30σ, 50σ and 70σ, followed by increments of 50σ. Near these strong sources, we find the r.m.s. noise to be 0.3 mJy beam−1.

Extended Data Figure 3 Cartoon depiction of a protostellar system, showing the outflow (12CO emission), envelope (C18O emission) and disk (unresolved).

Contributions to blueshifted and redshifted molecular line emission are indicated along the outflow and envelope, assuming that the outflow is nearly in the plane of the sky with respect to the observer.

PowerPoint slides

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Plunkett, A., Arce, H., Mardones, D. et al. Episodic molecular outflow in the very young protostellar cluster Serpens South. Nature 527, 70–73 (2015). https://doi.org/10.1038/nature15702

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/nature15702

This article is cited by

Comments

By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.

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