GAL04

Proposal

Proposal: GAL04: Newly discovered GeV-emitting SNR G17.8+16.7
PI: Hideaki Katagiri (hideaki.katagiri.sci@vc.ibaraki.ac.jp)

  Source:

    RA (J2000) 261.069 (17h24m16.56159917s) 

    DEC (J2000) -5.145 (-05d08m41.98175399s) 


    The corresponding galactic coordinate is (l, b) = (17.89751883, 16.7474377).
    Note: The wrong position (the radio center) was described before July 10, 2023. Please use the above values.

    The position is the best-fit position based on the Fermi-LAT gamma-ray analysis by Araya et al (2022).
    The Fermi-LAT paper is https://ui.adsabs.harvard.edu/abs/2022MNRAS.510.2920A/abstract . 
    The position is given by Araya by private communication.
    The assumed shape is the Gaussian with the containment radius of about 0.68 degree.
    Since R.A. is around 18h, the observation would be around June (3+(18-12)/2=6).

    The radio center for reference:
    RA (J2000) 261.04375 (17h24m10.5s) 

    DEC (J2000) -5.18125 (-5d10m52.5s) 

    The corresponding galactic coordinate is  (l, b) = (17.85158111, 16.75082053).

Observational settings/limits

-  Wobble observation with a large offset angle 
 Since this source is largely extended with the diameter of about 1.4 degree, the large Wobble offset angle is required. 
 In the proposal, we set the Wobble angle as 0.9 degree. 
Note (July 10, 2023) : I misunderstood the wobble angle in the proposal, where I just gave them as the
position angles (angle from declination) that are used in astropy. The angle from right ascension is used for the above.

 The positions can be:

W0.90+105 <SkyCoord (ICRS): (ra, dec) in deg     (260.83542173, -4.27562657)>

W0.90+285 <SkyCoord (ICRS): (ra, dec) in deg    (261.30321739, -6.01428815)>

W0.90+000 <SkyCoord (ICRS): (ra, dec) in deg    (261.97264022, -5.14436356)> 

W0.90+180 <SkyCoord (ICRS): (ra, dec) in deg    (260.16535978, -5.14436356)>

The above can be used as a double check.

- In the proposal, we set the maximum zenith angle as 45 degree and require Dark observation to suppress systematic uncertainties.
  Since this source is largely extended, these requirements would be necessary.
- The joint MAGIC observations are not required.