Proposal: 1LHAASO J0056+6346u

Title: Identification, localization and modeling of the PeVatron candidate 1LHAASO J0056+6346u

Authors: G. Pirola, M. Strzys, E. Molina, Y. Chai, J. Jurysek, D: Green, G. Emery, H. Costantini, H. Katagiri

File:Proposal LST LHAASO J0056 gpirola.pdf

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Comments

 Comments from conveners:

Dear Giorgio, all,

We have been reading in some detail the proposal on 1LHAASO J0056+6346u. All in all it reads very good: it is very well justified both from a technical point of view and from the scientific side. Please find some doubts and a few minor comments below, which hopefully can help in making the proposal even stronger.

In the “MAGIC+LST RATIONALE” Section you correctly describe the outcomes of the MAGIC TAC for the combined proposal of this source together with 1LHAASO J2002+3244u. Following the MAGIC TAC results, the 130h of requested time are approved only as a “category-C” ranking, and therefore “these might be observed when their visibility falls in periods with lower oversubscription”, and hence are not really granted.

- We are requesting 50h, which is the same amount proposed for the MAGIC-only observations (35h in case MAGIC+LST). It is not clear to me how are these 50h computed, assuming that MAGIC has a somewhat better sensitivity w.r.t LST-1 (note that I am not considering that at least some data could already have been taken with MAGIC+LST when LST-alone starts to observe the source).

- In this regard, it is true that the lower sensitivity of LST-1 can be compensated by its larger FoV and a flat off-axis acceptance with offsets up to 1 degree (note in this regard the recent discussion about this, it seems that it is “safe” up to even 1.5 degrees if I remember correctly)

- In the “Technical Justification” we refer to Fig. 2 for the comparison with the HGPS fluxes, this I think should be Fig. 1

- For Fig. 2, I’m unsure on why assuming a lower E-threshold the required observing times for a 5 sigma detection does not go down (for a soft spectrum we should gather many more statistics below, say, 1 TeV, and hence have a faster source detection, no?). I think it is reasonable to take 1 TeV for these estimates, but I don’t understand the flat curves below ~400 GeV. Is this the (approximated) result of the convolution of the source spectrum and the LST-1 sensitivity?