From ccarilli@aoc.nrao.edu Tue Aug  6 12:17:00 2002
Date: Thu, 01 Aug 2002 07:21:23 -0600
From: Chris Carilli <ccarilli@aoc.nrao.edu>
To: Steve Rawlings <sr@astro.ox.ac.uk>
Subject: AGN -- notes / we'll need to fill in forms for them

Heino Falcke wrote:

> Chris:
>
> As I told you, this is the worst of time for me to respond to all of
> the SKA questions. As you know this all came very quick and so I
> couldn't do much about it. I am sitting here during my summer vacation
> and try to connect to the internet through my mobile phone.
>
> I will therefore only send a very brief reply (without the forms) to
> the WP designs. I will also restrict myself to three level 1 science
> goals from the Bologna meeting (I gave you some more ideas in my
> previous email).
>
> I.  Detection of faint AGN from z=0 to z=infinity (to make it easy,
> ``faint'' is restricted to FRI radio galaxies). This requires: microJy
> sensitivity, 1'' resolution, simultaneous multi-frequency coverage
> (i.e., minimum two,better 4 widely separated IFs), fast source
> switching (large number of sources) and good snapshot image quality.
>
> - as far as I understand the sensitivity and resolution is met by all
>   designs, so the absolute minimum requirement is met by all.
>
> China: 2 IF is minimum, max IF sep. not specified, response time may
> be long for large surveys or monitoring campaign of many sources, if
> source switching takes that long.
>
> Europe: max sep. of IFs is OK, if only out to 1.4 GHz, however, at
> least 6 cm is needed for consistency with older surveys and to be
> sensitive for flat-spectrum sources. Multi-beaming and fast switching
> is big plus, of course.
>
> India: Freq. range OK, otherwise not enough information,
> source switching time may be long
>
> Australia 1: FOV good, source switching time may be long, what is
> max. IF sep.?
>
> Australia 2 (cyl. refl.): multibeaming and freq. coverage is OK, what
> is max. IF sep. and BW? How good is the beamshape in crowded fields
> for snapshots (e.g. to unambiguously pick out linear features like
> jets with their many pencil beams)?
>
> USA: everything fine, fast source switching may be a bit inefficient,
> sep. of IFs is OK for dual-freq. observations.
>
> II) high-brightness temperature radio cores to uncover even faint AGN
> and study relativistic outflows (requires in addition mas-scale
> resolution - at least as an expansion option)
>
> China: seems difficult to expand baseline. Europe & Austr. 1 are a bit
> on the short side too - needs to show expansion option, otherwise AGN
> are not well covered!
>
> III) H2O masers, requires 22 GHz and 10^4 spectral channels.
>
> Only US design meets these specs. The omission of H2O masers really
> hurts.
>
> That's it. Of course one could say more, e.g. about AGN variability
> monitoring (including Intra-Day-Variability of faint sources) and
> detection of outbursts with a transient monitor (that would probably
> benefit the European design), and circular polarization etc., which
> are not really covered by the form and can be quite significant.
>
> Best wishes
>
> Heino
>
> ----------------------------------------------------------------------------
>  ___      ___   _____   ___   _____  |PD Dr. Heino Falcke
> /__/\    /__/| /____/\ /__/| /____/\ |Max-Planck-Institut f. Radioastronomie
> |  \ \  /|  || |  o \/ |  || |  o \/ |Auf dem Hügel 69
> |  |\ \//|  || |  __/  |  ||f|  __/  |D-53121 Bonn, Germany
> |  ||\_/ |  || |  ||   |  || |  |\ \ |E-mail: hfalcke@mpifr-bonn.mpg.de
> |__|/    |__|/ |__|/   |__|/ |__|/\_||Fax: +49/(0)228/525-229
>                                      |Tel.: +49/(0)228/525-217
>              B O N N                 |Mobile: +49 178/5672532
>                                      |Email2SMS: 491785672532@sms.talkline.de
> ----------------------------------------------------------------------------
>               Web: http://www.mpifr-bonn.mpg.de/staff/hfalcke
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