Sub-millimeter Astronomy & Herschel Space Observatory

[madbadgalaxyman (Robert)]

Here is an absolutely brilliant article from physicsworld.com, Jan 3rd 2013, by Steve Eales, explaining clearly and interestingly the sub-millimetre (100 micrometers to 1 mm wavelengths) observations made by the JCMT and the Herschel Space Observatory.

In my view, the Herschel Space Observatory was more important than the Hubble Space Telescope, as a very large fraction of the universe became observable only when the Herschel Telescope came into action;
most of the universe is extremely cold, yet optically-dark matter at a chilly 10-30 degrees Kelvin "lights up like a christmas tree" in Herschel Telescope images!

In fact, I believe that the loss of the Herschel Space Telescope due to it running out of coolant was arguably the biggest disaster ever for the science of astronomy;
yes, this was planned for, but a short mission of only a few years was a colossal waste of a billion dollar 3.5-meter space telescope.

I have converted the article to Microsoft Word 2000 (.doc) format:

Submm Astronomy explained__(Steve Eales__PhysicsWorld__Jan 3rd 2013)Cool dust and baby stars.doc

Cheers,
mad galaxy man

Additional 'higher level' article added in edit :

For those of you who want an intermediate-level article, here is a good paper explaining the critically important role of the Herschel Space Telescope in figuring out how it is that stars form:

____SF_____NEW__prestellare cores_herschel survey characterised.pdf

[Ric]

I know I may be thinking a bit Utopian, but in this day and age of robotics you would think that they could have come up with a contingency plan for refilling the coolant.

When you think of skycranes and rovers and that type of technology, a small one way robotic satelite with a refill tank would not seem to be that far advanced.

[Steffen]

If the coolant is anything like printer ink the cost of refilling would be prohibitive

Cheers
Steffen.

[madbadgalaxyman (Robert)]

The problem with Herschel's rather short mission is that they only had time to point it at the things they already knew they were interested in, e.g. the distribution of dust in galaxies, and the inner structure of the regions where stars form.
So they never got a chance to point it at things that might lead to major and unforeseen discoveries.

Not a good idea to throw away billions of dollars worth of telescope that is working in an unexplored wavelength regime.

[xelasnave]

A full sky survey would be useful. Bootes void observation also useful.
Alex

[madbadgalaxyman (Robert)]

Hello Alex,

I absolutely agree with you; they should have done more observations of very-low-density regions such as intergalactic space and the voids, because of the extraordinary sensitivity of this telescope to the heat radiation (thermal emission, at far-infrared wavelengths) from extremely-low-temperature material in the universe.

A lot of the Herschel programmes revolved around observing the the details of the star formation process and observing the unbelievably complex 'goings on' in the interstellar medium within galaxies;
which is very understandable, because trying to figure out star formation has been an unsolved problem for a very long time...... and Herschel can peer into the middle of even the densest clouds of gas and dust - with minimal extinction.

Here is the list of the Herschel key programmes, which I assume they did carry out in full:
http://herschel.esac.esa.int/Key_Programmes.shtml

As you can see, the focus of Herschel observations was not on intergalactic space, which is a pity, as they might well have found something interesting there.
The intergalactic medium has not been a very mainstream topic of research till recently, and it is only recently becoming a part of the universe where actual objects are being detected by our telescopes; so perhaps the target list for Herschel would have included more intergalactic space, if the telescope had been launched today.

I do agree with you, they should have looked in the voids with Herschel, and in a few other 'unusual' places. But of course, the mission was too short for this.

This type of lack of imagination and 'thinking out of the box' in the targetting of the Herschel Space Observatory also applies very much to the targetting decisions that have been made for the Hubble Space Telescope. (as you will discover if you look at contents of the data archives for the HST)

Best regards,
Robert

[madbadgalaxyman (Robert)]

To illustrate what I mean by 'searching for the intergalactic gas', here is an image by Thilker and Braun, which shows the low-mass gas clouds surrounding M31.

The attached image is an overlay of the gas clouds (as detected from the HI radio spectral line that originates in neutral Atomic Hydrogen Gas) over a visible-light image of M31. The gas clouds are shown as contours.

The origin and evolution of these gas clouds is unknown; some of them could be falling into M31 and may have come from intergalactic space.

Another intriguing possibility is that some of these gas clouds could be 'dark galaxies'....... containing a large concentration of dark matter, plus a small amount of gas, but with no stars formed from the gas (as yet).



These clouds, for historical reasons only, are known as High Velocity Clouds, by analogy with similar clouds that were discovered around our own Milky Way Galaxy.

(( More recently, some more distant gas clouds have been detected between M33 and M31 that may not be associated with either galaxy))

[xelasnave]

I study nothing and say it does not exist. Once space was empty but even a void holds something. Do gallaxies line up like buttons on a string the string being a connection of material or matter I no longer have a link suggesting such ...I am a hermit and sole sailor with only a smart phone so is my excuse for lack of ccontribution.