Hot Gas – It’s What’s For Dinner

Herschel Finds Our Galaxy’s Black Hole Likes Hot Meals!

Artist’s impression of the Galactic Center. Credit: ESA – C. Carreau

In a region near the center of our Milky Way galaxy known as Sagittarius A* (Sgr A*, and yes, the * IS pronounced! -  ‘Sagittarius A-Star‘) lurks a Supermassive Black Hole. Apparently this local black hole of ours is preparing for a meal of hot gas.

With a mass of about 4 million times that of our Sun, and lying around 26,000 light-years away from our Solar System, our black hole is still a few hundred times closer to us than any other galaxy with an active black hole at its center. Detailed observations made by the European Space Agency’s (ESA) Herschel Space Observatory, (you know, BEFORE it did that whole running out of liquid helium coolant thing, So Long, Herschel), show hot molecular gas which may be orbiting or falling towards our hungry black hole.

Vast amounts of dust lie in the plane of the Milky Way between here and its center. At far-infrared wavelengths it’s possible to peer through the dust allowing Herschel’s scientists the chance to study the innermost region of our Galaxy in great detail. According to ESA (Herschel Reveals The Milky Way’s Warm Heart) new research based on spectroscopic data from Herschel has resolved the innermost portion of the Milky Way, a few light-years around Sgr A*, for the first time at far-infrared wavelengths. The team of astronomers, led by Javier Goicoechea from the Centro de Astrobiología in Madrid, Spain, was able to isolate the far-infrared emission from all the interstellar components that surround Sgr A* – neutral atomic, molecular and ionized gas, as well as dust.

A big surprise found by the team was how hot the molecular gas in the innermost central region of the Galaxy gets. At least some of it is around 1000ºC, much, MUCH, hotter than typical interstellar clouds (usually only a few tens of degrees above the –273ºC of absolute zero). Some of the heating is explained by the intense ultraviolet radiation coming  from a cluster of massive stars which hang out very close to the Galactic Center, but they alone aren’t enough to explain the high temperatures. In addition to this stellar radiation, Dr Goicoechea’s team hypothesize that emission from strong shocks in highly-magnetized gas in the region may be contributing to the high temperatures. Shocks such as these may be generated in gas cloud collisions, or in material flowing at high speed from stars and protostars.

‘The observations are also consistent with streamers of hot gas speeding towards Sgr A*, falling towards the very centre of the Galaxy,’ says Dr Goicoechea. ‘Our Galaxy’s black hole may be cooking its dinner right in front of Herschel’s eyes.’

To get a head-wrapping perspective on where this hot action is taking place in relation to our little neighborhood in the Orion Arm of the galaxy, check out this map of the Milky Way provided by Richard Powell. Also check out his web-site, The Atlas of The Universe, for an incredibly awesome and completely addictive interactive version of this map, as well as other equally time-devouring maps!

Oh yeah, and it seems that the Milky Way’s black hole isn’t the only hungry one! See that dwarf galaxy located on the far side of the galaxy from us? Sagittarius Dwarf Galaxy, discovered in 1994, is approximately 78,000 light years away and seemingly on our galaxy’s dinner menu. And apparently the Milky Way is a very sloppy eater leaving streams of star crumbs as it gobbles up it’s smaller neighbors.

The Sagan Series – Part 5 – Decide To Listen

Decide To Listen

Today I present Part 5 of Reid Gower‘s YouTube videos titled The Sagan Series. This edition focuses on one of Carl Sagan‘s primary passions; The Search for Extraterrestrial Intelligence (SETI) program.

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Message To Mars

Phoenix Lander on Mars

While Sagan’s interest in listening for signals from space was no secret, he also was no stranger to sending out messages. ‘Visions of Mars’ was a message sent from our world to future human inhabitants of the planet Mars. The message, encoded on an archival silica-glass mini-DVD, was launched to The Red on Aug 4, 2007 aboard the NASA Mars Lander Phoenix, arriving May 25, 2008.

The ‘Phoenix DVD’ on Mars.

The DVD, provided by The Planetary Society, contains a multimedia collection of literature and art about Mars, including, among others, the text of H.G. Wells‘ War of the Worlds and Ray Bradbury‘s The Martian Chronicles. There are also messages directly addressed to future Martian visitors or settlers from several space visionaries, including Sagan whose Visions of Mars message may be listened to here (It’s AWESOME, btw!). The DVD, claiming to be the ‘first library on Mars’, and rightfully so, also contains the names of a quarter million human space fans collected by The Planetary Society through the Internet. Sounds exciting? (The correct answer would be ‘YES’!!) Do you wish your name was included on that DVD presently sitting on the surface of another world? (Again, the response ‘YES’ works!) If so, then you’ll be excited to know that on May 1 NASA issued an invitation to members of the public to submit their names and a personal message online for a DVD to be carried aboard its Mars Atmosphere and Volatile Evolution (MAVEN) spacecraft scheduled for launch in November of this year! (Umm, the correct response here is ‘OH HELL YES!!!’)

 

 

NASA’s Mars Atmosphere and Volatile Evolution (MAVEN) spacecraft.

According to NASA, the DVD is part of the mission’s Going to Mars Campaign and will carry EVERY name submitted. (Even MINE!!) But, would you like MORE than just your name to be carried to The Red? If you said ‘HELL YES!’ then you’ll be extra excited to know that NASA is also encouraging the public to submit a message in the form of a three-line poem, or haiku. (OH, HELL NO! I suck at haiku!)

For those of you who don’t suck and would like to take part – there are rules, people! Only three (3!) haikus will be selected. The deadline for submissions is July 1. The top three messages will be selected by online vote which will begin July 15. Everyone participating in the Going to Mars campaign will be able to print a certificate of appreciation to document their involvement with the MAVEN mission. I’m thinking this would be an exciting project for classrooms to participate in, and apparently I’m not the only one thinking this…..

‘This new campaign is a great opportunity to reach the next generation of explorers and excite them about science, technology, engineering and math,’ said Bruce Jakosky, MAVEN principal investigator from CU/LASP. “I look forward to sharing our science with the worldwide community as MAVEN begins to piece together what happened to the Red Planet’s atmosphere.”

To find out more and take part visit Going To Mars with MAVEN!!!

MAVEN is the first spacecraft devoted to exploring and understanding the Martian upper atmosphere. The spacecraft will investigate how the loss of Mars’ atmosphere to space determined the history of water on the surface. Go MAVEN Go!!!

All images: NASA

A Saturn Storm and A Herschel Update

A Polar Hurricane

With cloud speeds clocking as fast as 330 miles per hour, and with an eye measuring a mind-blowing 1,250 miles across, the spinning vortex of Saturn’s north polar storm is both beautiful and awesome in its scope and power.

This false-color image from NASA’s Cassini spacecraft is among the first sunlit views of Saturn’s north pole captured by the craft’s imaging cameras. In 2004, when Cassini arrived in the Saturnian system, it was northern winter and the north pole was in darkness. The planet’s north pole was previously imaged under sunlight by NASA’s Voyager 2 in 1981, however the observation geometry did not allow for detailed views of the poles. As a result, it’s not known how long this newly discovered north-polar hurricane has been active.

Did he say ‘locked to the north pole’ and ‘no ocean underneath’?!! Ok, WOW!!

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. NASA’s Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA’s Science Mission Directorate. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo. Image Credit: NASA/JPL-Caltech/SSI

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So long Herschel, and thanks for all the Coolness….

The Large Magellanic Cloud galaxy in infrared light as seen by the Herschel Space Observatory. Image Credit: ESA/NASA/JPL-Caltech/STScI

According to a report yesterday, April 29, from the European Space Agency, the Herschel Space Observatory has exhausted its supply of liquid helium coolant and as such ended more than 3 years of pioneering observations of the ‘cool Universe‘. The event was not unexpected and confirmation came at the beginning of the spacecraft’s daily communication session with its ground station in Western Australia when a clear rise in temperatures was measured in all of Herschel’s instruments.

‘Herschel has offered us a new view of the hitherto hidden Universe, pointing us to a previously unseen process of star birth and galaxy formation, and allowing us to trace water through the Universe from molecular clouds to newborn stars and their planet-forming discs and belts of comets,’ said Göran Pilbratt, ESA’s Herschel Project Scientist.

Though the mission will not be making any more observations, discoveries from Herschel’s rich archives are expected to continue. ‘Herschel has improved our understanding of how new stars and planets form, but has also raised many new questions,’ said Paul Goldsmith, NASA Herschel project scientist at JPL. ‘Astronomers will be following up on Herschel’s discoveries with ground-based and future space-based observatories for years to come.’

For more information check out:

Herschel Closes Its Eyes On The Universe

Herschel Completes Its ‘Cool’ Journey in Space

Or my March 5th post – Herschel: Running On Empty

For a showcase of  Herschel images visit OSHI (Online Showcase of Herschel Images)