Recycling in the Universe Alyssa A. Goodman Department of Astronomy Harvard University In this stunning picture of the giant galactic nebula NGC 3603, the crisp resolution of NASA's Hubble Space Telescope captures various stages of the life cycle of stars in one single view. To the upper left of center is the evolved blue supergiant called Sher 25. The star has a unique circumstellar ring of glowing gas that is a galactic twin to the famousring around the supernova 1987A. The grayish-bluish color of the ring and the bipolar outflows (blobs to the upper right and lower left of the star) indicates the presence of processed (chemically enriched) material. Near the center of the view is a so-called starburst cluster dominated by young, hot Wolf-Rayet stars and early O-type stars. A torrent of ionizing radiation and fast stellar winds from these massive stars has blown a large cavity around the cluster. The most spectacular evidence for the interaction of ionizing radiation with cold molecular-hydrogen cloud material are the giant gaseous pillars to the right of the cluster. These pillars are sculptured by the same physical processes as the famous pillars Hubble photographed in the M16 Eagle Nebula. Dark clouds at the upper right are so-called Bok globules, which are probably in an earlier stage of star formation. To the lower left of the cluster are two compact, tadpole-shaped emission nebulae. Similar structures were found by Hubble in Orion, and have been interpreted as gas and dust evaporation from possibly protoplanetary disks (proplyds). The "proplyds" in NGC 3603 are 5 to 10 times larger in size and correspondingly also more massive. This single view nicely illustrates the entire stellar life cycle of stars, starting with the Bok globules and giant gaseous pillars, followed by circumstellar disks, and progressing to evolved massive stars in the young starburst cluster. The blue supergiant with its ring and bipolar outflow marks the end of the life cycle. The color difference between the supergiant's bipolar outflow and the diffuse interstellar medium in the giant nebula dramatically visualizes the enrichment in heavy elements due to synthesis of heavier elements within stars. This true-color picture was taken on March 5, 1999 with the Wide Field Planetary Camera 2. This picture is being presented at the 194th Meeting of the American Astronomical Society in Chicago. Credit: Wolfgang Brandner (JPL/IPAC), Eva K. Grebel (Univ. Washington), You-Hua Chu (Univ. Illinois Urbana-Champaign), and NASA

Recycling on Earth & In Galaxies

Recycling in the Universe

Making the First Recyclables... Fluctuations about 300,000 years after the Big Bang lead to “Structure Formation.” Gravitational collapse of some of these “structures” produces the first stars and galaxies.

Pretty young galaxies

Young Star with Outflow "Star Formation 101" Molecular Cloud Young Star with Outflow + Protoplanetary Disk Protostellar Core “Main Sequence” Star (with Planets)

Molecular Clouds: The Stuff of New Stars The Oschin telescope, 48-inch aperture wide-field Schmidt camera at Palomar Red Plate, Digitized Palomar Observatory Sky Survey

How much stuff is there? “Star-counting” Counts of stars per unit area measure how much material must be producing obscuration. Observations by Alves, Lada & Lada 1999

Radio Spectral-line Observations of Molecular Clouds

How do Optical & Radio Views Compare? Region of Radio Spectral-Line Survey Observations by Alves, Lada & Lada 1999

Cold, Dark & Dusty Gas and Dust are Very Cold in Molecular Clouds, T~10=100 Kelvin Dust at 10 K “Glows” in the Far-Infrared

Recycling in the Universe Storage & Collection in Interstellar Medium Discarding Processing, Production Consumption

Consumption of Recyclables The Hertzprung-Russell Diagram The "Initial Mass Function" (IMF) 0.01 2 3 4 5 6 0.1 1 Relative Number of Stars 10 100 Mass Relative to the Sun e.g. for every "Sun" there are 22 stars with mass 10x smaller than the Sun's

Stellar Recyclables The Hertzprung-Russell Diagram Spectacular contribution, and collection. Explosion injects, and "sweeps up" interstellar material. Supernova, then neutron star/pulsar or black hole Red giant then white dwarf Good recyclables. Red-giant wind main dust injection in ISM. Long-lived brown dwarfs "Styrofoam"

Stellar Winds: Discarding the Recyclables Mass=100 x Sun Eta Carinae was the site of a giant outburst about 150 years ago, when it became one of the brightest stars in the southern sky. Though the star released as much visible light as a supernova explosion, it survived the outburst. Somehow, the explosion produced two polar lobes and a large thin equatorial disk, all moving outward at about 1.5 million miles per hour. more than 8,000 light-years away Estimated to be 100 times more massive than our Sun, Eta Carinae may be one of the most massive stars in our Galaxy. It radiates about five million times more power than our Sun. The star remains one of the great mysteries of stellar astronomy, and the new Hubble images raise further puzzles. Eventually, this star's outburst may provide unique clues to other, more modest stellar bipolar explosions and to hydrodynamic flows from stars in general.

"Excess Gas?" (Post-red-giant planetary nebula) NGC 3918 is in the constellation Centaurus and is about 3,000 light-years from us. Its diameter is about 0.3 light-year. It shows a roughly spherical outer envelope but an elongated inner balloon inflated by a fast wind from the hot central star, which is starting to break out of the spherical envelope at the top and bottom of the image. Credits: Howard Bond (Space Telescope Science Institute), Robin Ciardullo (Pennsylvania State University) and NASA

Stellar Recyclables The Hertzprung-Russell Diagram Spectacular contribution, and collection. Explosion injects, and "sweeps up" interstellar material. Supernova, then neutron star/pulsar or black hole Red giant then white dwarf Good recyclables. Red-giant wind main dust injection in ISM. Long-lived brown dwarfs "Styrofoam"

Massive Stars & Supernovae Winds from O stars account for 30% of recylcable input to ISM Supernovae from O stars throw out much of the remaining mass Biggest contribution of (correlated) supernovae is to “collection”

HUBBLE CAPTURES DYNAMICS OF CRAB NEBULA A new sequence of Hubble Space Telescope images of the remnant of a tremendous stellar explosion is giving astronomers a remarkable look at the dynamic relationship between the tiny Crab Pulsar and the vast nebula that it powers. The colorful photo on the left shows a ground-based image of the entire Crab Nebula, the remnant of a supernova explosion witnessed over 900 years ago. The nebula, which is 10 light-years across, is located 7,000 light-years away in the constellation Taurus. The green, yellow and red filaments concentrated toward the edges of the nebula are remnants of the star that were ejected into space by the explosion. At the center of the Crab Nebula lies the Crab Pulsar -- the collapsed core of the exploded star. The Crab Pulsar is a rapidly rotating neutron star -- an object only about six miles across, but containing more mass than our Sun. As it rotates at a rate of 30 times per second the Crab Pulsar's powerful magnetic field sweeps around, accelerating particles, and whipping them out into the nebula at speeds close to that of light. The blue glow in the inner part of the nebula -- light emitted by energetic electrons as they spiral through the Crab's magnetic field -- is powered by the Crab Pulsar. The picture on the right shows a Hubble Space Telescope image of the inner parts of the Crab. The pulsar itself is visible as the left of the pair of stars near the center of the frame. Surrounding the pulsar is a complex of sharp knots and wisp-like features. This image is one of a sequence of Hubble images taken over the course of several months. This sequence shows that the inner part of the Crab Nebula is far more dynamic than previously understood. The Crab literally "changes it stripes" every few days as these wips stream away from the pulsar at half the speed of light. The Hubble Space Telescope photo was taken Nov. 5, 1995 by the Wide Field and Planetary Camera 2 at a wavelength of around 550 nanometers, in the middle of the visible part of the electromagnetic spectrum. Credit: Jeff Hester and Paul Scowen (Arizona State University), and NASA

Swept-up Gas:The Next Generation Far-infrared dust emission map of North Celestial Pole Loop, Pound & Goodman 1997 Spectral-line Emission from Gas In Cassiopeia Tóth et al. 1995

(At least) How much Gas is Swept-Up? ~20 pc Warning Globe Readers: Simple Algebra to Follow!

Recycling in the Universe Storage & Collection in Interstellar Medium Discarding Processing, Production Consumption

Young Stars do Their Share Too Giant Molecular Clouds "Cores" and Outflows Jets and Disks Solar System Formation

One Picture with the Whole Story Bipolar Wind from Massive Star Cluster of Main-Sequence Stars Molecular Cloud In this stunning picture of the giant galactic nebula NGC 3603, the crisp resolution of NASA's Hubble Space Telescope captures various stages of the life cycle of stars in one single view. To the upper left of center is the evolved blue supergiant called Sher 25. The star has a unique circumstellar ring of glowing gas that is a galactic twin to the famous ring around the supernova 1987A. The grayish-bluish color of the ring and the bipolar outflows (blobs to the upper right and lower left of the star) indicates the presence of processed (chemically enriched) material. Near the center of the view is a so-called starburst cluster dominated by young, hot Wolf-Rayet stars and early O-type stars. A torrent of ionizing radiation and fast stellar winds from these massive stars has blown a large cavity around the cluster. The most spectacular evidence for the interaction of ionizing radiation with cold molecular-hydrogen cloud material are the giant gaseous pillars to the right of the cluster. These pillars are sculptured by the same physical processes as the famous pillars Hubble photographed in the M16 Eagle Nebula. Dark clouds at the upper right are so-called Bok globules, which are probably in an earlier stage of star formation. To the lower left of the cluster are two compact, tadpole-shaped emission nebulae. Similar structures were found by Hubble in Orion, and have been interpreted as gas and dust evaporation from possibly protoplanetary disks (proplyds). The "proplyds" in NGC 3603 are 5 to 10 times larger in size and correspondingly also more massive. This single view nicely illustrates the entire stellar life cycle of stars, starting with the Bok globules and giant gaseous pillars, followed by circumstellar disks, and progressing to evolved massive stars in the young starburst cluster. The blue supergiant with its ring and bipolar outflow marks the end of the life cycle. The color difference between the supergiant's bipolar outflow and the diffuse interstellar medium in the giant nebula dramatically visualizes the enrichment in heavy elements due to synthesis of heavier elements within stars. This true-color picture was taken on March 5, 1999 with the Wide Field Planetary Camera 2. This picture is being presented at the 194th Meeting of the American Astronomical Society in Chicago. Credit: Wolfgang Brandner (JPL/IPAC), Eva K. Grebel (Univ. Washington), You-Hua Chu (Univ. Illinois Urbana-Champaign), and NASA

Recycling in the Universe(?)

Alyssa Goodman's upcoming article in Sky & Telescope Magazine For more information... cfa-www.harvard.edu/~agoodman and Alyssa Goodman's upcoming article in Sky & Telescope Magazine

(Unusual?) Stellar Nursery in the Eagle Nebula

Star Formation Caused by A Galaxy Collision (a. k. a Star Formation Caused by A Galaxy Collision (a.k.a. igniting the trash) Left A ground-based telescopic view of the Antennae galaxies (known formally as NGC 4038/4039) - so named because a pair of long tails of luminous matter, formed by the gravitational tidal forces of their encounter, resembles an insect's antennae. The galaxies are located 63 million light-years away in the southern constellationCorvus. Right The respective cores of the twin galaxies are the orange blobs, left and right of image center, crisscrossed byfilaments of dark dust. A wide band of chaotic dust, called the overlap region, stretches between the cores of the two galaxies. The sweeping spiral-like patterns, traced by bright blue star clusters, shows the result of a firestorm of star birth activity which was triggered by the collision. This natural-color image is a composite of four separately filtered images taken with the Wide Field Planetary Camera 2 (WFPC2), on January 20, 1996. Resolution is 15 light-years per pixel (picture element).