Professor Jacobs demonstrates a fork plane.

Starting this August I will be an Assistant Professor in the School of Earth and Space Exploration here at ASU! In my new role I will continue to do research in the LoCo Low frequency Cosmology group but also help the department continue to expand its cubesat and smallsat activities. In the near term this means acting as an advisor to current projects like Phoenix, a student cubesat project. In the longer term, cubesat sized technologies are enabling astronomical observations which until recently were not possible. The field of low frequency cosmology might ultimately be limited by the ionosphere and other planet-induced stability issues and require a space-based observatory. In the shorter term there are other interesting astronomy projects possible today, like for example dedicated observations of stars in the UV.

There will be upcoming opportunities for undergraduates, graduate students, and postdocs in areas like radio instrumentation, digital signal processing, cosmology analysis, smallsats and much more.

Just announced today, HERA has received a boost of $5.8M from the Gordon and Betty Moore Foundation. This comes on top of the most recent $9.5M grant from the National Science Foundation. The NSF support provided for a core of 250 dishes and enough infrastructure to record from them. Support from the Moore foundation allows us to replace the aging dipole feeds, legacy hardware from the PAPER array which are starting to show their age. The new dipoles will have a broader bandwidth response allowing us to reach further back into cosmic time to look for evidence of first stars letting off the first real heat. The additional support from the Moore Foundation also lets us fully build the 350 dish core as planned.

Update: Here is a nice article about the expansion which does a nice job explaining the physics.

This weekend, in a burst of activity with lots of hard work by students from ASU and Embry Riddle, it almost looks like we have dish. We’ve added the primary support pipes and in a marathon session of angle grinding, cut all the mesh pieces.  Next time we’ll be putting the rest of the supports and installing the mesh! Thanks again to everyone who came out on a Friday or Saturday. Especially the ASU undergrads who gave up some spring break!

Follow along on the google album

Mike, Callie, Nivedita, and Alicia test fit the first mesh pieces.


primary supports and cut mesh




Friday work crew.

Saturday work crew



Michael Busch is this year’s SESE Protostar!


Michael and Kali are always up for anything, including helping set up for teacher training on STARLAB.


Kali Johnson contemplates the vast acreage of the deflated Starlab dome. Will it fit back in its bag!?


Three undergrads unpack an ancient planetarium projector.


Six senior CS majors happy to have completed their year-long capstone project, designing an interface into 21 cm data. Good luck in the real world guys!

Science_November_2014_cosmic_dawnCheck out this article in Science magazine on Epoch of Reionization observations that really hits some interesting points not often covered in the media like the origin story of the MWA and LOFAR and the race to make a detection. Intrepid reporter Daniel Clery extracted some great quotes from the various PIs but my favorite is from Saleem Zaroubi:

To do what we do, you have to be hopelessly optimistic, but also brutally realistic.


ASU undergrad and AZ Space Grant intern Michael Busch has been stopping by my office this semester, helping me look at MWA cosmology data and learning about radio astronomy. Turns out he’s a Pillar of the Community! Among other things he’s a Residential Assistant, responsible for a passel of undergrads in the newly refurbished Manzanita dorm.  Last month he was nominated as a Excellent Student Leader by the res life folks and was asked to bring along his favorite faculty advisors (Judd and I, naturally) to the award Gala.  Here we are trying to look swank.  Well done Michael!


At the 2014 Student Leadership Gala. Left to Right: Judd Bowman, Michael Busch, Danny Jacobs

Here is a composite image of the entire sky in radio frequencies. It shows data from Parkes, Jodrell Bank and Effelsburg (ie the “Haslam map“, technically for you astro nerds the Global Sky Model by Angelica de Oliviera Costa which includes some data from other observations) as well as point sources from the VLA in the north and Molonglo in the south. This version is suitable for a 10x20inch poster. Those stars aren’t stars! Each is a radio galaxy undergoing a cataclysmic event emanating from a central million solar mass black hole. The nearest, double-lobed Centaurus A, features prominently center right. The radio Milky Way, a vast assemblage of supernova remnants, stretches across the center.

The sky in the FM radio radio band. A composite from many different telescopes around the world.

The sky in the FM radio radio band. A composite from many different telescopes around the world

Check out this MWA image of the galactic plane from David Kaplan (UWM). The image of 150MHz radiation covers 80 degrees wide and has a resolution of about 5 arcminutes. At about 125million pixels its a bit large to digest, so I’ve uploaded it to Gigapan, where you can pan and zoom ala google maps. Most of the circular things are supernova remnants, the imprints of ancient supernova explosions impressed on the galaxies plasma and magnetic fields.

This is just a sneak preview of the imaging capability of this fully operational battle station.


Low res thumbnail. Click image for full map at Gigapan.


A tiny fraction of the full resolution image. Look at all the supernova remnants! Click image for full map at Gigapan.



A nice composite of Centaurus A (as imaged by PAPER) and the moon to scale. Almost ten times the size of the moon, it really is a remarkable sight. Or would be if we could only see in the radio. For more, see Stefan et al.


Centaurus A, a nearby radio galaxy is remarkably close. imaged here by PAPER. The galactic plane stretches across the bottom. Image by: Chris Carilli, Irina Stefan, Composite by: Danny Jacobs.


Comparing PAPER and MWA fluxes to come up with a model relating the two. The blue dots are all equally possible to within 76%.

Title: The precision and accuracy of early Epoch of Reionization foreground models: comparing MWA and PAPER 32-antenna source catalogs

This paper compares the fluxes in the first PAPER and MWA catalogs.  These sources are the brightest foregrounds in front of the EoR HI emission.  Various estimates suggest that we have to subtract these guys to anywhere from 0.1 to 0.01%. Percent!! Also we need to know the flux precisely so we can calibrate our power spectrum.

These first catalogs turn out to be accurate to about 20%.  We also looked at sources that were measured twice by the MWA and found that they didn’t agree very well (20-50% or more) away from the center of the image.  This means that the primary beam model used to flatten the flux scale was off.  This is probably true for both experiments.

In the end we noted that though 20% is no where near where we need to be for precise EoR foreground subtraction or flux calibration, its not too shabby for two experimental arrays at first light!