[Nessc] NESSC meeting 27 on the outer heliosphere and the interstellar interaction

Wed Nov 21 20:14:34 EST 2018

Hi Paul,

Thank you very much for your e-mail. I am very happy that you also find the idea of remote sensing the outer heliosheath with secondary
He ENA’s interesting. It is very good that this idea sparked discussions which, as we all know, are important in science.

Let me say a few words on the measurements. These IBEX maps are pixel maps that consist of 60 longitudinal and 30 latitudinal pixels. It takes
6 month for one map. It is true that the secondary ENAs are visible in a smaller angle range but we have good number of pixels with secondary measurements.
Every pixel is a measurements. So, these maps are not a “single point measurement”, in fact,  these maps are multi-point measurements. 
In addition we have 8 energy steps so in principle we have 8 of these maps. Yes, for these measurements we only use the lower 3 energy steps. This, in addition,
increases the number of measurements by a factor of 3. Also, we can compare/combine measurements in any direction in the sky.

It is true that measurements alone will not give us the full picture, because these maps only show us the result of several physical processes generating these
ENA emissions measured by IBEX. At this point we do need theory and simulations to identify possible processes. In these simulations and theoretical consideration we
can control parameter for these processes and we might be able to identify dominant processes — including the flow field around the heliosphere. Indeed, we still
have a number of large parameters but comparing these models with observation we can limit the range of these parameters. So, these measurement can
be used for a “reality check” and the models —numerical or analytical— can provide us a better understanding of the global shape the heliosphere. 

I do not favouring one model, and I am not trying to validate any model at this point. However, I do think can use model results and compare them with measurements to infer/limit the parameter range of the variables. Phil’s model is one of them.

I do agree that this is a complex problem, but I also think that with this effort we can make progress in this matter. Please do not hesitate to contact me for any
information you might need.

Best regards and Happy Thanksgiving,
Harald

> On 21. Nov 2018, at 11:56, Song, Paul <Paul_Song at uml.edu> wrote:
> 
> Phil and Harald ,
> I assume that this email can reach both of you. if not, Nathan, could you forward to them?
> I am following the discussion we had on using the secondary He to probe the outer heliosheath, a very interesting idea.
> I repeat my comment that the observation shows only (possible) asymmetry of the sheath flow. This is a new (and single) piece of information. One should not use it to resolve more than one unknown. Otherwise it is over-interpretation of observation, a common mistake in today’s data analyses. Any model that is used in the deriving the data cannot be used to confirmed the model unless there is independent validation of the model. This was my comment of one can solve only one unknown from one equation.
>  
> With that said, I am following Phil’s idea. If there were no ISM magnetic field and the solar magnetic field, the flow around a body could be assumed as axial symmetric. The asymmetry observed can be caused by one or both magnetic fields. As I mentioned during the discussion, the ISM field effect tends to enhance the flow around the nose in the two tangential directions perpendicular to the ISM field. therefore, the asymmetry can be potentially used to infer the direction of the ISM field. in this case, one may not be able to infer the shape of the heliosphere. The solar magnetic field, on the other hand, tends to produce asymmetry relative to the dipole tilt, assuming to be north-south. In which direction enhancement can be seen depends on the heliospheric model. If the heliosphere is fatter in the flank, enhancement should be seen in the azimuthal direction. if the heliosphere is skinny as shown in Merav’s simulation, the enhancements should be in the latitudinal direction. The asymmetry can be compared with the these two field directions to determine which one is dominant. My feeling is that the ISM field most likely to be dominant.
>  
> Happy Holiday!
> Paul  
>  
> From: Nessc <nessc-bounces at lists.sr.unh.edu <mailto:nessc-bounces at lists.sr.unh.edu>> On Behalf Of Nathan Schwadron
> Sent: Saturday, October 6, 2018 6:24 PM
> To: NESSC NESSC <nessc at lists.sr.unh.edu <mailto:nessc at lists.sr.unh.edu>>
> Subject: [Nessc] NESSC meeting 27 on the outer heliosphere and the interstellar interaction
>  
> Announcing .. 
>  
> NESSC meeting 27 on the outer heliosphere and the interstellar interaction
> http://nessc.sr.unh.edu <https://urldefense.proofpoint.com/v2/url?u=http-3A__nessc.sr.unh.edu&d=DwMFaQ&c=lqHimbpwJeF7VTDNof4ddl8H-RbXeAdbMI2MFE1TXqA&r=Kl7E7qhYe9S-0HLhnCifj22AsDfNvLn8Lt2nxoU1nkI&m=ThAUL8XA2G-vjmiZOuy6dU9yehct8YfAJRz9EXNQTQs&s=jKVYBRPx3J17-zmMRhGRHz1Npo-9_BJ5hEtlbcQ7YOI&e=>
>  
> Monday November 19, 2018, 10 AM – 5 PM
> U Mass Lowell, UCC Building, Room UCC-158
> Parking is across in the Salem St. lot
>  
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>  
> Local Organizers: 
> Ofer Cohen <ofer_cohen at uml dot edu>
> Paul Song <Paul_Song at uml dot edu>
>  
> NESSC Organizers:
> Nathan Schwadron <nschwadron at unh dot edu>
> Merav Opher <mopher at bu dot edu>
>  
> Web Organizer:
> Ken Fairchild  <Ken.Fairchild at unh dot edu>
>  
> Over the last decade, observations from the Voyager Satellites, the Interstellar Boundary Explorer, and Cassini/INCA have ushered in an era of discovery concerning the previously unknown properties of the global heliosphere and its interaction with the local interstellar medium. Wide ranging observations including those of pickup ions, anomalous cosmic rays and suprathermal particles have significant implications for our understanding of global interstellar interactions.
>  
> This 27th meeting of the New England Space Science Consortium includes topics concerning the global heliosphere, the local interstellar medium, interstellar interactions, and related topics.  As always, we invite all members of the New England Space Science community to the meeting. And as in all meetings, we will include contributions from participants on wide-ranging topics.
>  
> Speakers Include:
> Merav Opher  (BU) - Global Heliosphere Simulations
> Paul Song (UML) – Analytical Approach to Interstellar Boundary Structure
> Adam Michaels (BU) – Simulations of the Global Heliosphere
> Marc Kornbleuth (BU) – Simulations of the Global Heliosphere
> Ofer Cohen (UML) – Modeling of the Heliosphere and Astrospheres        
> Fatemeh Rahmanifard (UNH) — Interstellar Neutral H from IBEX
> Eberhard Moebius (UNH) — Interstellar Neutral Atoms from IBEX and IMAP 
> Marty Lee (UNH)— Analytical Model of Interstellar Neutral Atoms
> Nathan Schwadron  (UNH) — IBEX observations of the Ribbon and Globally Distributed Flux over 9 years
> Harald Kucharek (UNH) – Secondary Neutral Atoms Observed by IBEX
> Phil Isenberg (UNH) – Analytical Modeling of Secondary Neutral Atoms Observed by IBEX
>  
> CHeers
>  
>  Nathan
>  
> Nathan Schwadron
> Presidential Chair
> Norman S. and Anna Marie Waite Professor
> University of New Hampshire
>  
> n.schwadron at unh.edu <mailto:n.schwadron at unh.edu>
> Morse Hall - Room 350
> 8 College Road
> Durham NH 03824
> USA
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