From the editor

Computing Bits was picked as the new name of the Computing Sector newsletter. We are much obliged to all of you who sent suggestions, which remained anonymous to all but me—and I didn't vote. I look forward to to continuing to work with you all on the articles and edit the newsletter with its new name. Huzzah!

~Marcia Teckenbrock

Sector news

--- Fermilab Computer Security Awareness Day is December 8. Learn about today's risks and how you can protect yourself online between 9 a.m. and 5 p.m. in Wilson Hall. In addition, staff will do USB drive scans at the doctor-is-in booth in the Wilson Hall Atrium. [View agenda]

--- There will be a localized power outage in FCC2 on Thursday, Dec. 1 at 8 a.m. The outage will affect twenty-one CMS computing racks and will last for approximately four hours. The work includes retiring the UPS3, preparing to remove the UPS4 later and retiring the last two water-based air conditioning units and AC water system in FCC.

--- FermiMail update: The email service team has successfully migrated 513 Exchange 2007 users to FermiMail and they expect all Exchange mailbox migration to be completed by Dec. 8.  Starting Dec. 12, the team will move on to migrate IMAP users, starting with Computing Sector. Lotus Notes mailbox migration is tentatively scheduled to happen in January 2012.

The team is also working with meeting room owners to develop procedures that will ease data migration for meeting rooms. 

--- Fermilab completed the FY2011 Financial Statement audit conducted by KPMG LLP. No findings/deficiencies were noted, which is the goal. The audit included a review of IT processes and systems and required data and input from members of various departments in the CCD.

--- The Sloan Digital Sky Survey (SDSS) was listed as having one of the "Ten Most Amazing Databases in the World " by Popular Science.

Person on mountain summit

We'll miss you!

Jason Allen (Fermilab Experiments Facilities)

Randoph Herber (Accelerator & Detector Simulation)

Kurt Ruthmansdorfer (High Performance Parallel Computing Facility)

Welcome, new employees

Soon Yung Jun (Accelerator & Detector Simulation)

Miroslaw Krynski (Network & Virtual Services)

Happy Anniversary!
(5, 10, 15 & 20+ years)

Ed Podschweit - 40 years
Bill Barker - 27 years
Lauri Loebel Carpenter - 25 years
Gene Oleynik - 24 years
Mark Thomas - 24 years
Neal Wilcer - 24 years
Phil Lutz - 23 years
Simon Kwan - 22 years
Wayne Baisley - 20 years
Robert Kennedy - 15 years
Maurine Mihalek - 15 years
Bakul Banerjee - 10 years
Griselda Lopez - 10 years

White dwarf stars—calibrating the cosmos

White dwarf star candidates within the DES footprint
Candidate white dwarf stars within the area to be mapped by the Dark Energy Survey.
Images courtesy Douglas Tucker

The Experimental Astrophysics group’s Douglas Tucker spent some time early this month in Chile, where he observed white dwarf stars at the Cerro Tololo Inter-American Observatory for some preliminary work for the Dark Energy Survey (DES). The survey itself will also take place at the observatory using the Victor M. Blanco 4-meter telescope; however, Tucker and another researcher from Austin Peay State University in Tennessee used the 1-meter telescope for their 11-night run.

The purpose of the observation was to confirm whether stars suspected to be DA white dwarfs actually are. These particular stars are observed not only because there are a lot of them within the DES footprint, but also because they have a pure hydrogen atmosphere, which results in a smooth spectrum that makes taking measurements and analyzing data easier. Thanks to cooperation from the weather, about half of the candidate stars were successfully observed, many more than originally anticipated.

Scientists will use confirmed DA white dwarfs as calibration stars for DES. The images they take during observation provide data such as how many photons are detected—or how bright the star appears to be. “But observed brightness needs to relate to a physical quantity like watts per meter-squared or some other measure of brightness,” says Tucker. “You do that by using stars of known brightness, so when DES observes these stars later, we’ll already know their brightness and can then calibrate other stars and galaxies in the DES using these stars.”

White dwarf star candidate target
To confirm that the target star (circled) is a white dwarf, researchers use analysis software to compare the star's magnitude of brightness to that of known stars (known as a "standard" stars). To do this, they must pass through various photometric filters (r=red, g=green, u=ultraviolet).
Click image
for an animation to illustrate responses for various filter passbands.

Tucker and his colleagues took advantage of results from a previous study that were published a few months ago that cut down on the number of potential white dwarfs. Until then, no good catalogs of such stars in the southern skies existed. The study used data from a multi-decade-long photographic sky survey and then compared stars’ movement relative to other stars.

“White dwarfs are stars, like our sun,” says Tucker. “Unlike our sun, though, they’ve used most of their fuel and are near the end of their lifecycle, so they’re usually not very bright. If you see them, they’re probably pretty close to the earth.” And stars close to the earth appear to move faster in the sky.

To cull the sample from that study, Tucker observed in three different photometric filters developed by the Sloan Digital Sky Survey. “As it turns out, if you plot how bright they are in these different filters, DA white dwarfs appear to be very blue.”

The morning after each night's observing, raw data from the observatory was synchronized to the bluearc disk at Fermilab—a total of 15 Gigabytes for the 11-night run. The data will be processed on the EAG SDSS/DES computing cluster using a suite of python scripts based on code originally developed for another project by Liz Buckley-Geer and Huan Lin and extensively modified by Tucker.

Once the researchers have a sample of good white dwarfs, they will use a spectrograph during an additional observing run to take and measure spectra of the stars. This data will help further understand the characteristics of each star so that they may be used as calibration stars in DES.

~ Marcia Teckenbrock

Core Computing Spotlight

Here's a new feature we're excited about. Each month, a member of the Core Computing Division will discuss their work and how it impacts Fermilab. Maung Han has graciously agreed to kick off this feature.

Maung Han
Core Computing/Network and Virtual Services/Network Services

Maung Han

"My role in providing networking services to the laboratory includes the design, implementation and support of the data infrastructure as well as the services that run on top of it. I was recently involved with the Internet edge network migration project which re-routed the majority of lab Internet traffic over fully diversified and redundant paths. As a result, the lab can now tolerate a single network path failing and still be able to access offsite areas. 

My current focus areas include configuring VPN, which allows people off site to remotely access some of the lab’s restricted resources such as servers, websites and control applications; working with the network team and lab management to establish a five-year plan for the wireless infrastructure that provides lab-wide Wi-Fi access; and configuring and deploying the VoIP systems that provide voice communications to the TD IB3A building. In addition, I am involved in a project to migrate all remote-access users to the new VPN infrastructure using a more robust and user-friendly client."

Kitchen fire safety
flame in a frying pan

Take a look at this short but dramatic video on how to put out a kitchen fire involving grease or oil. The key here is to use a wet towel that has been wrung out, not dripping wet. Water thrown on a grease fire becomes instantly superheated and blows the burning grease up and out, burning you or spreading the fire! Share this with your loved ones!

~ Amy Pavnica