1 / 28

Exploring Stellar Formation: Outflows, Clouds, and the Cycle of Star Birth and Death

This presentation by Alyssa A. Goodman from Harvard University's Department of Astronomy delves into the intricate processes of star formation, including the phenomena of outflows from dying stars, molecular clouds, and their impact on stellar nurseries. It discusses the cycle of star birth and death, emphasizing how supernovae and jets influence molecular clouds and star clustering. Additional topics include the role of magnetohydrodynamic waves, thermal motions, and insights from radio spectral-line observations, offering a comprehensive understanding of our galaxy's dynamic interstellar medium.

chipo
Télécharger la présentation

Exploring Stellar Formation: Outflows, Clouds, and the Cycle of Star Birth and Death

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Watching New Stars Form Alyssa A. Goodman Harvard University Department of Astronomy cfa-www.harvard.edu/~agoodman

  2. "Cores" and Outflows 1 pc = 3 lyr Molecular or Dark Clouds Jets and Disks Solar System Formation What we (think we) understand

  3. Outflow from Dying Star Young Star Cluster Stellar Nurseries Nebulosity/Glowing Gas The Cycle of Star Birth & Death

  4. Outflow from Dying Star Young Star Cluster Stellar Nurseries Nebulosity/Glowing Gas The Cycle of Star Birth & Death

  5. 100 mm Dust Emission in Cassiopeia Tóth et al. 1995 Some Molecular Clouds "Created" by Supernovae

  6. "Cores" and Outflows 1 pc = 3 lyr Molecular or Dark Clouds Jets and Disks Solar System Formation What we (think we) understand

  7. Magnetohydrodynamic Waves Infall Outflows MHD Turbulence Thermal Motions What we also understand, but don’t always admit SNe/GRB H II Regions

  8. “Dust, Not Holes”

  9. Time Showed Barnard was Right! Barnard’s Optical Photograph of Ophiuchus IRAS Satellite Observation, 1983 Remember: Cold (10K) dust glows, like a blackbody, in the far-infrared.

  10. Night Vision

  11. Dust, not Holes The Oschin telescope, 48-inch aperture wide-field Schmidt camera at Palomar Red Plate, Digitized Palomar Observatory Sky Survey

  12. Tutorial:Velocity from Spectroscopy Observed Spectrum Telescope  Spectrometer 1.5 1.0 Intensity 0.5 0.0 -0.5 All thanks toDoppler 100 150 200 250 300 350 400 "Velocity"

  13. Tutorial:Velocity from Spectroscopy Observed Spectrum Telescope  Spectrometer 1.5 1.0 Intensity 0.5 0.0 -0.5 All thanks toDoppler 100 150 200 250 300 350 400 "Velocity"

  14. My Main Line of Work: Radio Spectral-line Observations of Interstellar Clouds

  15. The 1000-ft Telescope at Arecibo, PR

  16. Radio Spectral-line Observations of Interstellar Clouds Radio Spectral-Line Survey Alves, Lada & Lada 1999

  17. Velocity as a "Fourth" Dimension Loss of 1 dimension No loss of information

  18. “Integrated Intensity Map” Region of Radio Spectral-Line Survey Alves, Lada & Lada 1999

  19. 1957 H I Spectroscopy Telescope  Spectrometer H I Spectrum of the Galaxy M51 from Agassiz Station,Heeschen 1957 All thanks toDoppler

  20. 1950 1960 1970 1980 1990 2000 8 10 4 10 7 10 N 6 channels, 10 channels 3 10 *N N 5 10 channels pixels S/N in 1 hour, 2 10 4 10 (S/N)*N N 3 10 1 N 10 pixels pixels 2 10 0 10 1950 1960 1970 1980 1990 2000 Year Learning More from “Too Much” Data Product S/N

  21. Magnetohydrodynamic Waves Infall Outflows MHD Turbulence Thermal Motions The Dynamic Star-FormingInterstellar Medium SNe/GRB H II Regions

  22. “Giant” Herbig-Haro Flows:PV Ceph 1 pc Reipurth, Bally & Devine 1997

  23. A New Proposal: Episodic ejections from precessing or wobbling moving source Required motion of 0.25 pc (e.g. 2 km s-1 for 125,000 yr)

  24. 67:55 H H 3 1 5 C H H 3 1 5 B 67:50 H H 3 1 5 A H H 4 1 5 HH 215P2 ) 0 HH 215P1 5 9 1 ( PV Cephei d 67:45 HH 315D H H 3 1 5 E 67:40 H H 3 1 5 F 20:46 20:45 ( 1 9 5 0 ) a PV Ceph 12CO (2-1) OTF Map from NRAO 12-m Red: 3.0 to 6.9 km s-1 Blue: -3.5 to 0.4 km s-1 Arce & Goodman 2001

  25. NASA’s Origins Program

  26. More Questions? • cfa-www.harvard.edu/~agoodman

More Related