Wine and Cheese Spring 2016: Difference between revisions
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An important factor limiting our ability to understand the production and propagation of cosmic rays pertains to the effects of heliospheric forces, commonly known as solar modulation. The solar wind is capable of generating time and charge-dependent effects on the spectrum and intensity of low energy (~10 GeV) cosmic rays reaching Earth. Previous analytic treatments of solar modulation have utilized the force-field approximation, in which a simple potential is adopted whose amplitude is selected to best fit the cosmic-ray data taken over a given period of time. Making use of recently available cosmic-ray data from the Voyager 1 spacecraft, along with measurements of the heliospheric magnetic field and solar wind, I will show a time, charge and rigidity-dependent model of solar modulation that can be directly compared to data from a variety of cosmic-ray experiments. This is a simple analytic formula that can be easily utilized in a variety of applications, allowing us to better predict the effects of solar modulation and reduce the number of free parameters involved in cosmic ray propagation models. | An important factor limiting our ability to understand the production and propagation of cosmic rays pertains to the effects of heliospheric forces, commonly known as solar modulation. The solar wind is capable of generating time and charge-dependent effects on the spectrum and intensity of low energy (~10 GeV) cosmic rays reaching Earth. Previous analytic treatments of solar modulation have utilized the force-field approximation, in which a simple potential is adopted whose amplitude is selected to best fit the cosmic-ray data taken over a given period of time. Making use of recently available cosmic-ray data from the Voyager 1 spacecraft, along with measurements of the heliospheric magnetic field and solar wind, I will show a time, charge and rigidity-dependent model of solar modulation that can be directly compared to data from a variety of cosmic-ray experiments. This is a simple analytic formula that can be easily utilized in a variety of applications, allowing us to better predict the effects of solar modulation and reduce the number of free parameters involved in cosmic ray propagation models. | ||
== William Blaire == | |||
== | '''Understanding the Curious Young Supernova Remnant Population in M83''' <br> | ||
''' | The nearby starburst galaxy M83 has been host to at least six (and likely seven!) supernovae in the last century, many of the core-collapse type. Hence, one might expect dozens of young SN remnants similar to, say, Cas A in our Galaxy or E0102-7219 in the SMC. We have used deep Chandra observations in conjunction with HST WFC3 imaging to find and diagnose the young SN remnants in M83 and, by in large, they do not look like Cas A (that is to say, dominated by emission from SN ejecta). Rather, they appear to be bright radiative remnants like the Cygnus Loop even though they are much smaller and younger. This rapid evolution into the radiative phase may be unique to the M83 population, due to high metal abundances and a high pressure ISM. Our investigation is ongoing, with Gemini GMOS spectroscopy of many of these young SN remnants providing additional clues. | ||
=February 1st= | =February 1st= | ||
Revision as of 17:22, 28 January 2016
This page records the schedule, titles and abstracts of the JHU/STScI CAS Astrophysics Wine & Cheese Series in Spring 2016.
If not specified otherwise, the talks are a 25-min presentation plus a 5-min Q/A session.
Back to W&C Schedule
January 25th
Ilias Cholis
Towards a predictive analytic model for the solar modulation of cosmic rays
An important factor limiting our ability to understand the production and propagation of cosmic rays pertains to the effects of heliospheric forces, commonly known as solar modulation. The solar wind is capable of generating time and charge-dependent effects on the spectrum and intensity of low energy (~10 GeV) cosmic rays reaching Earth. Previous analytic treatments of solar modulation have utilized the force-field approximation, in which a simple potential is adopted whose amplitude is selected to best fit the cosmic-ray data taken over a given period of time. Making use of recently available cosmic-ray data from the Voyager 1 spacecraft, along with measurements of the heliospheric magnetic field and solar wind, I will show a time, charge and rigidity-dependent model of solar modulation that can be directly compared to data from a variety of cosmic-ray experiments. This is a simple analytic formula that can be easily utilized in a variety of applications, allowing us to better predict the effects of solar modulation and reduce the number of free parameters involved in cosmic ray propagation models.
William Blaire
Understanding the Curious Young Supernova Remnant Population in M83
The nearby starburst galaxy M83 has been host to at least six (and likely seven!) supernovae in the last century, many of the core-collapse type. Hence, one might expect dozens of young SN remnants similar to, say, Cas A in our Galaxy or E0102-7219 in the SMC. We have used deep Chandra observations in conjunction with HST WFC3 imaging to find and diagnose the young SN remnants in M83 and, by in large, they do not look like Cas A (that is to say, dominated by emission from SN ejecta). Rather, they appear to be bright radiative remnants like the Cygnus Loop even though they are much smaller and younger. This rapid evolution into the radiative phase may be unique to the M83 population, due to high metal abundances and a high pressure ISM. Our investigation is ongoing, with Gemini GMOS spectroscopy of many of these young SN remnants providing additional clues.
February 1st
Name
Title
Abstract
February 8th
David Hogg
Title
Abstract
February 15th
Name
Title
Abstract
February 22nd
Mubdi Rahman
Title
Abstract
Richard Anderson
Title
Abstract
February 29th
Name
Title
Abstract
March 7th
Nathan Miller
Title
Abstract
Duncan Watts
Title
Abstract
March 15th Spring break
March 21st
Name
Title
Abstract
March 28th
Ravi Sankrit
Title
Abstract
Zhilei Xu
Title
Abstract
April 4th
Name
Title
Abstract
April 11th
Name
Title
Abstract
April 18th
Name
Title
Abstract
April 25th
Name
Title
Abstract
May 2nd
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Title
Abstract
