Archive for the ‘HIFI’ Category

HIFI back and how!

May 4, 2010

The HIFI instrument, the high resolution spectrometer on Herschel, had a bad start, with a serious technical fault early in the mission. The fault was diagnosed and fixed and I’ve just seen some astounding spectra from it. The reason why high resolution is so important is that it can reveal the velocity of gas flows in, for example, forming stars and can determine the molecules that make up gas clouds etc. in interstellar space.

The spectra just shown – merely a taster of what is to come – show unexpected velocity structures and the discovery of new molecular species. HIFI is back and, despite the fact that it doesn’t do my kind of science, it’s clear it will be doing some spectacular things!

Herschel HIFI Spectrum of Orion in the News

March 13, 2010

Two page feature on the HIFI spectrum of Orion in the London Metro newspaper yesterday.

HIFI Returns!

January 15, 2010

Reports from various places, including its builders SRON and the BBC reveal that the HIFI instrument on Herschel is now back to full working order.

This is great news for Herschel as it means its third instrument, which gives it high resolution spectroscopic capabilities needed to fully understand the chemistry and physics of star formation, is back!

There’s a whole lot of information about recent science results we hope to post over the next few weeks as well.

HIFI wakes from its slumber

December 8, 2009

Some excellent news to report – the HIFI instrument on Herschel (the high resolution spectrometer) has been successfully switched on after lying dormant for 4 months, after suffering an unwanted voltage peak in the electronic system of HIFI, which in August led to a faulty diode in a DC/DC convertor.

After several months of troubleshooting and the development of a new operating procedure to prevent a similar occurence, HIFI was commanded to switch on using its redundant electronics chain on Sunday, followed by an upload of revised software and a “Short Functional Test” – a complete HIFI health check. All were carried out successfully.

The next step in HIFI’s rehab comes in the new year – the instrument was only starting its performance verification effort, so an an intense post-Christmas re-commissioning and calibration campaign is required to bring HIFI back up to speed and ready to use for regular observing as per SPIRE and PACS.

First look at Herschel Spectroscopy

November 27, 2009

ESA put out a major release today showing the first results from the spectrographs on Herschel. The release includes data on the Orion star formation region, on nearby and distant galaxies, on a massive star about to become a supernova and on a comet in our own solar system. The latter set of data was taken with HIFI before the technical fault that has left it shut down, awaiting a restart early next year.

These spectroscopic observations show the huge potential of Herschel to show us the physical and chemical processes going on inside dusty objects, be they star formation regions in our own galaxy, or in luminous interacting galaxies like Arp220 and Mrk231. My own research interests are more focussed on the distant luminous objects, and the data shown here from two archetypical ULIRGs (Ultraluminous Infrared Galaxies) are really spectacular. Never before have we seen the rich range of spectral lines that PACS and SPIRE have revealed in these objects.

PACS also holds out the hope of examining the velocity structure of some of these lines. This is particularly interesting in Mrk231 which hosts not only a massive burst of star formation but also a supermassive black hole powering a hugely luminous active galactic nucleus (AGN). The relationship between galaxy interactions and mergers in triggering both starbursts and AGNs is a hot topic, and Mrk231 makes an ideal testbed.

Finally, for sheer spectral richness and complexity, the PACS spectrum of the massive star VYCMa takes some beating. There’s a huge amount of physics and chemistry in this spectrum of a star deep into its old age and soon to become a supernova. Unfortunately this isn’t my area, so hopefully someone will add comments describing what the data means for this object.

For more information and coverage of these results see the ESA web release, BBC News Online, and the SPIRE website at Cardiff University.

HIFI to make a come back in 2010

November 20, 2009

A comment from Gert reveals the news that HIFI will be returning to operations in 2010. This is the third instrument on Herschel alongside SPIRE and PACS. It’s been suffering from technical difficulties which have been investigated for the last several months. A fix has now been determined and we hope that it will rapidly return to full operation once it’s been turned back on.

A full report can be found here.

Good news!

HIFI troubles in Nature

September 15, 2009

The science journal Nature has some more details of the issues we’re having with the HIFI instrument on Herschel.

Bottom line is that HIFI are still trying to understand the problem, but can switch to the redundant power supply and things should work again. In the mean time PACS and SPIRE are doing fine and their PV phase work has been accelerated. In fact, some science observations are beginning to be taken. For one of the programmes I’m involved with some were taken on Sunday, though we won’t get the data to look at for some time.