Tuesday UVa / NRAO Astronomy (TUNA) Lunch Talks - Fall 2006

A series of informal, brown-bag, lunchtime seminars for the discussion of current projects and astronomical news

The schedule

August 2006
Sunday Monday Tuesday Wednesday Thursday Friday Saturday

1
Al Wootten, NRAO - Charlottesville, VA: "The Cornell-Caltech Atacama Telescope: Science and Synergy with ALMA"
2
Scott Ransom, NRAO - Charlottesville, VA: "Transient, Wacky, and Stong Radio Pulses from a Magnetar"
3
4
Nicole Gugliucci, NRAO - Charlottesville, VA: "REU Presentations"
5
6
7
8
Claire Davy & Destry Saul, NRAO - Charlottesville, VA: "REU Presentations"
9
Jennifer Katz, Lucy Frey & Lecky Stone, NRAO - Charlottesville, VA: "REU Presentations"
10
11
Gerrit L. Verschuur, Physics Department - University of Memphis: "The Pervasive Presence of a 34 km/s Wide HI Emission Profile."
12
13
14
15
16
17
18
19
20
21
22
23
24
25
Yuefang Wu,Dept of Astronomy - Peking University: "Inflow Motion in High-Mass Star Formation Regions"
26
27
28
29
Open TUNA Spot
30
31

1 August 2006
Al Wootten: NRAO - Charlottesville, VA
The Cornell-Caltech Atacama Telescope: Science and Synergy with ALMA

Abstract: TBA

2 August 2006
Scott Ransom: NRAO - Charlottesville, VA
Transient, Wacky, and Stong Radio Pulses from a Magnetar
or
Soon all your K- through Q-band GBT time will be mine too!

Abstract:

Recently, we found extremely strong and variable radio pulsations from an Anomalous X-ray Pulsar (AXP). This is the first detection of radio pulsations from a magnetar. The pulsations are unlike those from most radio pulsars (in many ways), and indicate that the magnetosphere of the neutron star is changing on day-to-week timescales. With its flat spectrum and incredibly stong and narrow pulses, it may prove to be a unique probe of interstellar scintillation and molecules (OH, Formaldehyde, H20, ...) as well. Observations with Parkes, the GBT, Nancay, IRAM, etc are ongoing.

3 August 2006
Nicole Gugliucci: NRAO - Charlottesville, VA
REU Presentations

Abstract: TBA

8 August 2006
Claire Davy & Destry Saul: NRAO - Charlottesville, VA
REU Presentations

Abstract: TBA

9 August 2006
Jennifer Katz, Lucy Frey & Lecky Stone: NRAO - Charlottesville, VA
REU Presentations

Abstract: TBA

11 August 2006
Gerrit L. Verschuur: Physics Department - University of Memphis
The Pervasive Presence of a 34 km/s Wide HI Emission Profile.

Abstract:

Analysis of HI emission profile shapes and a review of the literature have revealed abundant evidence to suggest that a 34 km/s wide component is widespread. To better understand HI structure and before comparing HI data with other markers in interstellar space, this background signal must be subtracted. Possible mechanisms for forming this broad component will be discussed.

25 August 2006
Yuefang Wu: Dept of Astronomy - Peking University
Inflow Motion in High-Mass Star Formation Regions.

Abstract: TBA

September 2006
Sunday Monday Tuesday Wednesday Thursday Friday Saturday
1
2
3
4
5
Darryl Leiter, Marwood Astrophysics Research Center: "OBSERVATIONS SUPPORTING THE EXISTENCE OF AN INTRINSIC MAGNETIC MOMENT INSIDE THE CENTRAL COMPACT OBJECT WITHIN THE QUASAR Q0957+561."
6
7
8
9
10
11
12
David Lee Nidever, Astronomy Department - University of Virginia: "Tracking the Magellanic Stream(s): From Point of Origin to 100 degrees away."
13
14
15
16
17
18
19
Ken Kellermann, NRAO - Charlottesville, VA: "Update on the SKA"
20
21
22
23
24
25
26
Juan Uson, NRAO - Charlottesville, VA: "Superthin Galaxies"
27
28
29
30

5 September 2006
Darryl Leiter - Marwood Astrophysics Research Center
OBSERVATIONS SUPPORTING THE EXISTENCE OF AN INTRINSIC MAGNETIC MOMENT INSIDE THE CENTRAL COMPACT OBJECT WITHIN THE QUASAR Q0957+561.

Abstract:

The above Harvard CFA press release and attachments describe important new research by Rudolph Schild, Darryl Leiter, and Stan Robertson. The paper on this new discovery has been recently published in the July 2006 issue of The Astronomical Journal. In the paper reference to (Astro-ph/0505518) which is a longer version of the published paper that contains the detailed theoretical appendixes that were used to support the results discussed in the shorter version of the paper published in The Astronomical Journal.

In the above work it has been shown that recent auto-correlation and fluctuation analysis of the time series data in the brightness curves and gravitational micro-lensing size scales seen in Q0957+561 A,B has provided observational evidence for the existence and characteristic physical dimensions of a new non-standard internal structure contained within this quasar.

What is most important is the fact that it we have found that the TOTALITY OF THE FOUR DYNAMIC COMPONENTS which make up this new internal quasar structure CANNOT be explained in terms of standard black hole based theories such as Kerr black hole dynamo or Magnetically Arrested Accretion Disk models. Instead we have found that the new non-standard internal structure contained within this quasar can be consistently explained only in terms of a new class of gravitationally collapsing solutions to the General Relativistic Einstein-Maxwell field equations which describe highly red shifted radiating, Eddington limited, Magneto-spheric, Eternally Collapsing Objects (MECO) which contain observable intrinsic magnetic moments since they do not have event horizons.

Hence discovery of this new internal structure within Q0957+561 is profound since: a) implies that this quasar contains an observable intrinsic magnetic moment anchored to the central rotating compact MECO contained within it and, b) represents strong observational evidence that the central compact object within this quasar does not have an event horizon.

12 September 2006
David Lee Nidever: Astronomy Department - University of Virginia
Tracking the Magellanic Stream(s): From Point of Origin to 100 degrees away.

Abstract:

We explore the nature of the Magellanic Stream with the new Leiden- Argentine-Bonn (LAB) all-sky HI survey (Kalbera et al. 2005). We decompose the HI profiles into Gaussians using an automated Gaussian analysis program similar to that by Haud (2000). We find that the Magellanic Stream is composed of two filaments, as first pointed out by Putman et al. (2003), distinguishable along the entire length of the Stream visible in our dataset. One of the filaments originates in the 30 Dor region in the Large Magellanic Cloud (LMC). From the spatial and velocity variations of this filament the drift rate of the Magellanic Stream gas is estimated to be ~30 km/s, which gives an age of ~3 Gyr for the Magellanic Stream. We also analyze the Leading Arm and find that many of its features are continuous and also connect to the 30 Dor region in the LMC. This is further evidence that tidal forces contributed to the creation of the Magellanic Stream.

19 September 2006
Ken Kellermann: NRAO - Charlottesville, VA
Update on the SKA

Abstract:

Over the past 6-12 months the SKA has seen considerable progress worldwide. I will report on the current Reference Design, site selection status, governance issues, status of the national and regional pathfinders, operations and funding issues, and possible roles for the U.S. and NRAO.

26 September 2006
Juan Uson: NRAO - Charlottesville, VA
Superthin Galaxies

Abstract: TBA

October 2006
Sunday Monday Tuesday Wednesday Thursday Friday Saturday
1
2
3
Anne Verbiscer, Astronomy Department - University of VA: "Observations of Saturn's Satellites at True Opposition: Probing the Microstructure of Icy Regolith"
4
5
6
7
8
9
Rudy Schild, Harvard-Smithsonian Center for Astrophysics: "Quasar Structure from Radio and Optical Microlensing and Reverberation of Lensed System Q0957+561 A,B"
10
Joannah Hinz, Astronomy Department - University of Arizona: "Spitzer Observations of Dwarfs and Low Surface Brightness Galaxies"
11
12
13
14
15
16
17
Anthony Remijan, NRAO - Charlottesville, VA: "A SLiSE of Splatalogue"
18
19
20
21
22
23
24
25
26
27
28
29
30
31
Miller Goss,NRAO - Socorro, NM: "The Impact of Solar Radio Astronomy on the Development of Radio Astronomy Techniques- 1945 to 1951."

3 October 2006
Anne Verbiscer: Astronomy Department - University of VA
Observations of Saturn's Satellites at True Opposition: Probing the Microstructure of Icy Regolith

Abstract: TBA

9 October 2006
Rudy Schild - Harvard-Smithsonian Center for Astrophysics
Quasar Structure from Radio and Optical Microlensing and Reverberation of Lensed System Q0957+561 A,B

Abstract:

Extensive radio and optical monitoring of the first discovered gravitational lens have produced an important legacy of brightness records, originally collected to establish time delay and determination of the Hubble Constant. Today they are being processed to study the nature of the baryonic dark matter, and quasar structure. Microlensing of the radio emitting region has identified the size and brightness of the core, and reverberation has located the core above the accretion disc plane. Optical microlensing has identified sharp structure associated with the inner edge of the accretion disc, and a broad emitting region at the location of the emission line Elvis structures. Reverberation analysis reveals the exact sizes and locations of these surfaces, together with the exact inclination and orientation of the quasar. This empirical structure aligns well with the MECO theory of quasar structure described here recently by Dr. Darryl Leiter, wherein the highly redshifted compact central object has an intrinsic magnetic dipole field whose magnetic propellor produces the observed structures.

10 October 2006
Joannah Hinz - Astronomy Department - University of Arizona
Spitzer Observations of Dwarfs and Low Surface Brightness Galaxies

Abstract:

Dwarfs are considered to be the building blocks of which all more luminous systems are formed, yet are one of the least studied types of galaxies with regards to dust and metal content due to their faint nature in the infrared. Similarly, low surface brightness galaxies may represent a significant component of the baryonic matter in the universe, but have never been detected at mid-infrared wavelengths, with the conclusion that their dust emission and extinction is negligible. New Spitzer observations of a small sample of dwarfs and low surface brightness galaxies open the door to understanding the true distribution, mass, and extent of both the warm and cool dust components in these objects, addressing crucial issues regarding their chemical and stellar evolution. IR observations of these types of galaxies are critical if we are to understand galaxy evolution with a view that is unbiased by optical luminosity.

17 October 2006
Anthony J. Remijan: NRAO - Charlottesville, VA
A SLiSE of Splatalogue

Abstract:

The ALMA Working Group on Spectral Line Frequencies is dedicated to generating a collated and rationalized database of spectral line frequencies, transitions and line strengths from radio to infrared wavelengths that can be used by the entire astronomical community interested in spectral line astrophysics.

Currently, the commonly used databases that are used for spectral line searches, the JPL and CDMS databases, do not describe transitions in a user-friendly way, and where the catalogs overlap, the descriptions have to be compared and resolved to be consistent. Furthermore, the Lovas/NIST database tabulates only /observed/ interstellar transitions, but it does provide the user with a much better representation of molecular transitions by using a full description of the molecular transition. The NRAO Spectral Line Catalog (Splatalogue) is an attempt to collate, rationalize and extend existing spectroscopic resources for use by the astronomical community. The JPL, CDMS and the Lovas/NIST database provide an enormous amount of data - collecting the data in all three online databases together generates over 3.5 million transition data entries across almost 700 molecular species.

SLiSE is a data display tool that currently contains archival data. As a part of SLiSE, there is a function to overlay possible molecule identifications based on a current line catalog as well as overlaying H and He recombination lines. It is a java based applet that is platform independent and can be accessed online. Currently the online version does not have the capability to upload your own dataset but the stand alone version does. We are in the process of syncing both applications so you can upload your own data. It is simple and straightforward to use.

31 October 2006
Miller Goss: NRAO - Socorro, NM
The Impact of Solar Radio Astronomy on the Development of Radio Astronomy Techniques- 1945 to 1951.

Abstract:

In the first years after World War II radio astronomy experienced a rapid growth in Australia, the United Kingdom and the US due to the advances made in radar technology in the previous 6 years. Much of the early research was in the field of solar radio astronomy. The techniques of interferometry, aperture synthesis, dynamic spectra were developed by groups of astronomers in the UK and Australia and to a lesser extent in the US. Early connections with the exisiting optical astronomy commnunities were forged by these groups. The early recognition of the importance of free free emission in astrophysics was made by the early groups working on the hot corona of the sun.

The fact that one of the largest sunspot groups of the 20th century occurred in Feb 1946 played a major role in advancing radio astronomy techniques. The discovery of the radio sources by Bolton et al in Australia (Taurus A, Cen A , Virgo A etc) was influenced by the success of the solar group of Pawsey and Payne-Scott.

I will summarize a number of the impacts that the solar groups in Australia at CSIRO and in the UK (Hey's group and the group at the Cavendish under the leadership of Martin Ryle) made on the early years of radio astronomy.

November 2006
Sunday Monday Tuesday Wednesday Thursday Friday Saturday
1
2
3
4
5
6
7
Patrick Murphy, NRAO - Charlottesville, VA: "The Mercury Transit of November 2006"
8
9
10
Holiday
11
12
13
14
Rachel Osten, Astronomy Department - University of Maryland: "Super Flares and Killer Electrons"
15
16
17
18
19
20
21
Thanksgiving Week
22
23
Thanksgiving Day
24
25
26
27
28
Frank De Lucia, Physics Department - The Ohio State University: "Weeds, Flowers, Clutter and a New Approach to Removing the Spectroscopic Bottleneck in Millimeter and Submillimeter Astrophysical Spectra - A Discussion"
29
30

7 November 2006
Patrick Murphy: NRAO - Charlottesville, VA
The Mercury Transit of November 2006

Abstract:

This short talk covers the fundamentals of the upcoming transit of Mercury across the sun's disk, including a brief history of transits, what the transit is good for, and how, when and where we might best observe it safely. This is a relatively rare event; the next one won't be until 2016.

No particular expertise level is required to benefit from this talk; all staff are encouraged to come!

14 November 2006
Rachel Osten: Astronomy Department - University of Maryland
Super Flares and Killer Electrons

Abstract:

The Swift satellite, with its large field of view and quick response time, was designed to study GRBs. However, its characteristics also make it ideal to study bright transient events on more nearby interlopers. I will describe the serendipitous observation of a superflare from the nearby binary II Peg, which provided a few "firsts" and superlatives. I will discuss the importance of this flare in the context of stellar flare physics as well as impact on the stellar environment.

28 November 2006
Frank De Lucia: Physics Department - The Ohio State University
Weeds, Flowers, Clutter and a New Approach to Removing the Spectroscopic Bottleneck in Millimeter and Submillimeter Astrophysical Spectra - A Discussion

Abstract:

The current millimeter and submillimeter spectroscopic paradigm that grew out of molecular structural analysis is no longer capable of keeping up with the rapidly increasing spectroscopic power of modern astronomical instruments. This is because the time required for spectral analysis of the many low lying vibrational and torsional states of abundant molecular species exceeds by a significant factor all of the spectroscopic work on these species to date. In a series of talks at astronomical meetings over the last year, we have laid out an alternative spectroscopic approach that has the potential to break this bottleneck. This more experimental approach, which is based on the measurement of complete, intensity calibrated spectra over a wide range of temperatures, will have the greatest impact if there is a close wording relation between astronomers and spectroscopists. Viewgraphs that are designed to be the starting point for such a discussion will be presented.

December 2006
Sunday Monday Tuesday Wednesday Thursday Friday Saturday
1
2
3
4
5
Open TUNA Spot
6
7
8
Gordon Hurford, Space Science Lab - University of California, Berkeley: "Visibility-based Imaging of Solar X-Rays and Gamma-Rays with RHESSI"
9
10
11
12
Open TUNA Spot
13
Dunc Lorimer,Department of Astronomy -West Virginia University: "The Galactic Pulsar Population."
14
15
16
17
18
19
Open TUNA Spot
20
21
22
23
24
Christmas Eve
25
Christmas Day
26
Open TUNA Spot
27
28
29
30/31

8 December 2006
Gordon Hurford: Space Science Lab - University of California, Berkeley
Visibility-based Imaging of Solar X-Rays and Gamma-Rays with RHESSI

Abstract:

TBD

13 December 2006
Dunc Lorimer: Department of Astronomy - West Virginia University
The Galactic Pulsar Population.

Abstract:

I will present results from a recent statistical study using surveys carried out with the Parkes multibeam surveys. The multibeam system, a 13-pixel receiver operating at 20 cm wavelength, has revolutionized our view of the Galactic population of canonical pulsars and provides interesting new constraints on the Galactic distribution of free electrons. Predictions for current and future pulsar surveys will also be presented.