Some atomic physics u H I, O III, Fe X are spectra –Emitted by u H 0, O 2+, Fe 9+ –These are baryons u For absorption lines there is a mapping between.

Slides:



Advertisements
Similar presentations
The Birth of Stars: Nebulae
Advertisements

Chapter 19: Between the Stars: Gas and Dust in Space.
Cloudy u Accurate simulation of physical processes at the atomic & molecular level –“universal fitting formulae” to atomic processes fail when used outside.
Looking at the Interstellar Medium
Star Stuff Joy Harjo (1951 – ) from Secrets From the Center of the World I can hear the sizzle of newborn stars, and know anything of meaning, of the fierce.
Einstein Fellows Symposium 10/27/ Orly Gnat, Caltech In Collaboration with : Amiel Sternberg, Chris McKee.
The Formation and Structure of Stars
The Interstellar Medium ( 星際物質 、星際介質 ) Chapter 10.
Injection of Small Bodies into the ISM by Planetary Nebulae. Bob O’Dell University of Chicago 18 April 2007.
The Interstellar Medium Physical Astronomy Professor Lee Carkner Lecture 12.
Magnetic fields in Orion’s Veil T. Troland Physics & Astronomy Department University of Kentucky Microstructures in the Interstellar Medium April 22, 2007.
ISM & Star Formation. The Interstellar Medium HI - atomic hydrogen - 21cm T ~ 0.07K.
Lessons from other wavelengths. A picture may be worth a thousand words, but a spectrum is worth a thousand pictures.
Hydrostatic Equilibrium and the Sun’s Core:. Clicker Question: What does does ionized Helium, He II, contain? A: He nucleus only B: He nucleus and one.
Jonathan Slavin Harvard-Smithsonian CfA
ASTR112 The Galaxy Lecture 6 Prof. John Hearnshaw 10. Galactic spiral structure 11. The galactic nucleus and central bulge 11.1 Infrared observations Galactic.
STAR BIRTH. Guiding Questions Why do astronomers think that stars evolve? What kind of matter exists in the spaces between the stars? Where do new stars.
Astrophysics from Space Lecture 8: Dusty starburst galaxies Prof. Dr. M. Baes (UGent) Prof. Dr. C. Waelkens (KUL) Academic year
The Interstellar Medium Chapter 14. Is There Anything Between the Stars? The answer is yes! And that “stuff” forms some of the most beautiful objects.
Physical Conditions in Orion’s Veil Nicholas Abel – University of Cincinnati, Clermont Campus Collaborators: Crystal Brogan, Gary Ferland, Bob O’Dell,
6 th IRAM 30m Summer School Star formation near and far A. Fuente Observatorio Astronómico Nacional (OAN, Spain) Photon Dominated Regions I. Physical conditions.
Lecture Outlines Astronomy Today 8th Edition Chaisson/McMillan © 2014 Pearson Education, Inc. Chapter 18.
The Interstellar Medium. I. Visible-Wavelength Observations A. Nebulae B. Extinction and Reddening C. Interstellar Absorption Lines II. Long- and Short-Wavelength.
SCATTERING OF RADIATION Scattering depends completely on properties of incident radiation field, e.g intensity, frequency distribution (thermal emission.
Chapter 4: Formation of stars. Insterstellar dust and gas Viewing a galaxy edge-on, you see a dark lane where starlight is being absorbed by dust. An.
Lecture 14 Star formation. Insterstellar dust and gas Dust and gas is mostly found in galaxy disks, and blocks optical light.
ASTR112 The Galaxy Lecture 8 Prof. John Hearnshaw 12. The interstellar medium (ISM): gas 12.1 Types of IS gas cloud 12.2 H II regions (diffuse gaseous.
AS 4002 Star Formation & Plasma Astrophysics Supercritical clouds Rapid contraction. Fragmentation into subregions –Also supercritical if size R ≥ clump.
Note that the following lectures include animations and PowerPoint effects such as fly-ins and transitions that require you to be in PowerPoint's Slide.
VNGS science highlight: PDR models of M51 [CII]/[OI]63 ([CII]+[OI]63)/F TIR Similar gas properties in arm and interarm regions. Higher densities and stronger.
The Interstellar Medium
New advances in photoionization codes, how and what for? New advances in photoionization codes: Barbara Ercolano, UCL How and What for?
Review for Quiz 2. Outline of Part 2 Properties of Stars  Distances, luminosities, spectral types, temperatures, sizes  Binary stars, methods of estimating.
Radio Astronomy Emission Mechanisms. NRAO/AUI/NSF3 Omega nebula.
The Formation and Structure of Stars
What we look for when we look for the dark gas * John Dickey Wentworth Falls 26 Nov 2013 *Wordplay on a title by Raymond Carver, "What we talk about, when.
Lecture 30: The Milky Way. topics: structure of our Galaxy structure of our Galaxy components of our Galaxy (stars and gas) components of our Galaxy (stars.
The Interstellar Medium and Star Formation Material between the stars – gas and dust.
Stellar Formation 1)Solar Wind/Sunspots 2)Interstellar Medium 3)Protostars 4)A Star is Born October 23, 2002.
Star Formation Why is the sunset red? The stuff between the stars
Minimum to run Cloudy u Must specify –SED – shape of the radiation field –Flux of photons per unit area –Gas density u May specify –Gas composition, grains.
AGN Outflows: Observations Doron Chelouche (IAS) The Physics of AGN Flows as Revealed by Observations Doron Chelouche* Institute for Advanced Study, Princeton.
The Interstellar Medium. Red, White, and Blue : Nebulae.
Chapter 11 The Interstellar Medium
Simulated [CII] 158 µm observations for SPICA / SAFARI F. Levrier P. Hennebelle, E. Falgarone, M. Gerin (LERMA - ENS) F. Le Petit (LUTH - Observatoire.
Radio Galaxies part 4. Apart from the radio the thin accretion disk around the AGN produces optical, UV, X-ray radiation The optical spectrum emitted.
8 -The Interstellar Medium. Emission-Line Nebulae H II Regions Planetary Nebulae Supernova Remnants.
Turbulence and Magnetic Field Amplification in the Supernova Remnants Tsuyoshi Inoue (NAOJ) Ryo Yamazaki (Hiroshima Univ.) Shu-ichiro Inutsuka (Kyoto Univ.)
Universe Tenth Edition
The Lives of Stars. Topics that will be on the test!! Apparent and Absolute Magnitude HR Diagram Stellar Formation and Lifetime Binary Stars Stellar Evolution.
The Formation of Stars. I. Making Stars from the Interstellar Medium A. Star Birth in Giant Molecular Clouds B. Heating By Contraction C. Protostars D.
H205 Cosmic Origins  Today: The Origin of Stars  Begin EP 6  Tuesday Evening: John Mather  7:30 Whittenberger APOD.
ISM & Astrochemistry Lecture 1. Interstellar Matter Comprises Gas and Dust Dust absorbs and scatters (extinguishes) starlight Top row – optical images.
Note that the following lectures include animations and PowerPoint effects such as fly ins and transitions that require you to be in PowerPoint's Slide.
Star Formation The stuff between the stars Nebulae Giant molecular clouds Collapse of clouds Protostars Reading
“Globular” Clusters: M15: A globular cluster containing about 1 million (old) stars. distance = 10,000 pc radius  25 pc “turn-off age”  12 billion years.
Takashi Hosokawa ( NAOJ ) Daejeon, Korea Shu-ichiro Inutsuka (Kyoto) Hosokawa & Inutsuka, astro-ph/ also see, Hosokawa & Inutsuka,
Cloudy: Numerical Simulations of Plasmas and their Spectra If a picture is worth a thousand words, a spectrum is worth a thousand pictures Understanding.
The Interstellar Medium (ISM)
Note that the following lectures include animations and PowerPoint effects such as fly ins and transitions that require you to be in PowerPoint's Slide.
The Interstellar Medium and Star Formation
Star Formation & Main-sequence Stars
The Interstellar Medium and Star Formation
Galactic Astronomy 銀河物理学特論 I Lecture 1-6: Multi-wavelength properties of galaxies Seminar: Draine et al. 2007, ApJ, 663, 866 Lecture: 2011/11/14.
The Birth of Stars.
The ISM and Stellar Birth
Life of a Star Formation to Red Giant
The Interstellar Medium
Note that the following lectures include animations and PowerPoint effects such as fly ins and transitions that require you to be in PowerPoint's Slide.
Instructor: Gregory Fleishman
Presentation transcript:

Some atomic physics u H I, O III, Fe X are spectra –Emitted by u H 0, O 2+, Fe 9+ –These are baryons u For absorption lines there is a mapping between these two –H I absorption is produced by H 0

Emission lines are ambiguous u H I emission is produced by –Recombination of H + –Impact excitation of H 0 u So H I lines trace H + or H 0, depending on circumstances u The H + region around a hot star produces H I emission u A hot star produces successive layers of H +, H 0, H 2

The primary mechanism 2012 Cloudy workshop

Luminosity of H II region u Set by total luminosity in ionizing photons ObjectL(Ha)Stars Orion M Dor

A non-equilibrium gas u Gas emitting spectrum has a very low density, exposed to a range of radiation fields and particles u Populations of levels, ionization, spectrum, determined by many micro-physical processes u Not characterized by a single temperature

Physical state of interstellar gas u Non-equilibrium microphysics –Te: heating & cooling –Ionization & chemistry u Grain physics –Heats gas, attenuates radiation field u Predict full spectrum u All done self-consistently –Few free parameters –Goal is no free parameters

groups.yahoo.com/neo/groups/cloudy_simulations/infogroups.yahoo.com/neo/groups/cloudy_simulations/info

Runaway O star H II regions u ~1/4 of O stars are runaways –Expelled from close binary by explosion or instability u Pass by diffuse ISM and photoionize it u H II region is –Very faint –Very low density –Small magnetic field, B ~ 6  G u The H II region is an innocent bystander

California Nebula APOD Xi Persei

Ferland+09 MNRAS, 392, 1475

Star forming H II regions u Hot young stars very close to the molecular cloud that formed it u Ionizing radiation and stellar winds strike nearby molecular cloud

ESO

NASA/CXC/PSU/L.Townsley et al.; Infrared: NASA/JPL

Idealized structure of an H II region Hot H + bubble Warm H + “H II region” Warm H 0, H 2 “PDR” Cool H 2 “molecular cloud”

Flow of evaporating material  H 2  H 0  H +

Will Henney, Morelia

Guedel Science 319, 309

OMC, 13 CO To Earth Figure 8.4, Osterbrock & Ferland AGN3

2012 Cloudy workshop

Extinction map u Combined VLA radio continuum, HST optical recombination lines u Lighter shade  greater extinction u O’Dell & Yusef-Zadeh 2000, AJ, 120, 382

The “real” Orion Nebula O’Dell and Yousef-Zadeh 2000

A Orion veil – B los from HI Zeeman effect Component A u Colors – B los

Grains in H II regions u Grains survive in the warm H + layer u Were they destroyed, very strong Ca, Fe, and Al lines would be present –Kingdon&Ferland 1995, ApJ, 439, 793 u Grains very likely destroyed, or never formed, in hot H + bubble u Commonly cited claim that grains do not exist in warm H+ layer is due to wrong geometry –See BFM, 1991, ApJ, 374, 580, Section 4.5

Idealized structure of an H II region Hot H + bubble Warm H + “H II region” Warm H 0, H 2 “PDR” Cool H 2 “molecular cloud”

The BFM Orion Model u The equation of state – how does the density vary with depth into the cloud? u Warm H + layer is hydrostatic u Starlight radiation pressure balancing gas pressure u Model stopped at H + - H 0 ionization front, where gas changes phase from warm H + to warm H 0

M 17

Orion and M 17 (not to scale) Pellegrini+ 2007, ApJ 658, 1119 Orion M17

Orion and M 17 (to scale) Pellegrini+ 2007, ApJ 658, 1119 Orion M17

Zeeman H I B field ~500 μG Brogan Troland 2001, AJ, 560, 821

Magnetostatic equilibrium u Starlight pushes back surrounding material u Field lines coupled to gas, so compressed u Establishes magnetic version of hydrostatic equilibrium –Outward momentum of starlight balanced by magnetic pressure in PDR u Establishes simple relationship between hot bubble, warm H +, and warm H 0 regions Pellegrini+ 2007, ApJ 658, 1119