Slashdot Mirror

If you'd like a preview, check out the results from BLAST (more results and even prettier pictures coming out very soon). Although it only has a 1.8 meter mirror, it has the same version of detectors that the SPIRE instrument on Herschel uses. To be cheaper and faster, BLAST flys on a high-altitude balloon platform. Slashdot has covered it in the past. And there's a documentary about BLAST as well (also covered by slashdot).

Disclaimer: I work on the BLAST project.

True. But the oldest galaxies (what Herschel is mainly designed to look at) don't emit in the visible, even in their own (rest) frame. That's because the earliest galaxies are very dusty, and all this dust is opaque to the visible light. The stars are still there, glowing away, but their light is absorbed by this dust. This absorption heats the dust, warming it to 35K (give or take), which, as all things with non-zero temperature do, emits radiation like a blackbody. This light is then redshifted such that it's blackbody spectrum peaks in the submillimeter, which is what Herschel looks at.

Disclaimer: I work on BLAST, a balloon-borne experiment (cheaper than a satellite) which has detectors nearly identical to the ones of the SPIRE (main) instrument on Herschel.

However, if you do the math, you'll see that even the earliest possible galaxies (redshift = z = 10 (or less)) don't get visible light redshifted into the submillimeter (where Herschel looks). This is because the earliest galaxies are very dusty, and this dust obscures most of the visible light coming from the stars. However, to obscure the light, the dust is absorbing the energy, heating the dust up (to about 35K give or take) and this dust re-radiates at like 10-100 microns or so, which is redshifted into the submillimeter (200-600 microns) that Herschel looks at.

I work on a precursor to the SPIRE instrument (a major instrument on Herschel, called BLAST which flew on a high-altitude balloon (you need to get about the atmosphere to look in the submillimeter and balloons are way cheaper than sattelites).

And it's not really a Spitzer replacement, as it's looking at mostly longer wavelengths than Spitzer. It complements both. Virtually all different wavelengths are worth looking at as they all tells us unique things.

Herschel, mostly with the SPIRE instrument, will be looking at the earliest star forming galaxies. A nearly identical instrument to SPIRE was flown on a high-altitude balloon, BLAST, which got Slashdot coverage as well.

Disclaimer: I work on the BLAST project.

I'm sure some of the researchers are at McMurdo, and haven't yet gone home to their respective institutions.

I was there last year to help launch BLAST, which was up in the air at the same time as two other experiments, ANITA and SBI. Wait, that's also 3 simultaneous experiments. Weird record. I guess they didn't count SBI last year since it has pointing issues and they terminated the flight within 12 hours since it was unable to get any science. I felt bad for them. But there were 3 balloons up at the same time (that was a first for Antarctica).