13. Follow-Up Advocate (FA) Manual: Exercise Sheet

13. Follow-Up Advocate (FA) Manual: Exercise Sheet#

Section 13.1: Multiple-Choice Questions#

  1. What is the primary role of the Follow-Up Advocate (FA) during a gravitational wave alert?

    • a) To analyze the data from the telescopes

    • b) To notify the telescope teams and coordinate observations

    • c) To write scientific papers on gravitational waves

    • d) To monitor the weather conditions at observation sites

  2. When do you report to your WC?

    • a) After every GCN.

    • b) At every GW alert.

    • c) When you decide to follow up on an event.

    • d) Only at the end of your shift.

  3. When do you report to a core team member?

    • a) For an event you are unsure of.

    • b) When the WC is not responding.

    • c) At the start of every shift.

    • d) Never.

  4. Do we report every GCN we receive?

    • a) Yes, every GCN is added to skyportal comments.

    • b) No, all GCN are ignored.

    • c) No, we only upload photometry for the events we are observing.

    • d) Yes, all are added to the photometry table.

Section 13.2: Short Answer Questions#

  1. What do you include in skyportal comments for an alert? Can you give an example?

  2. Describe the process for determining whether a gravitational wave alert is high-profile.

  3. What are the key tasks involved in notifying telescope teams after a gravitational wave alert?

  4. What should you do if images have been uploaded to the OwnCloud and you are the on-duty FA?

  5. Explain the importance of including upper limits in a GCN Circular.

  6. What should you write in the #shifters channel when you start a shift?

  7. Why do you need to turn on notifications for the #gwalerts during your shift?

  8. Do you need to be in front of your computer for the entire shift, or can you do other tasks simultaneously?

  9. What is the role of a follow-up advocate? What about a weekly coordinator?

  10. What should you do when you start and end your shift?

Section 13.3: Scenario-Based Questions#

Scenario 1:#

Context: You receive a gravitational wave alert that appears to be a BNS merger within 150 Mpc, and the localization area is 180 deg².
Question: Describe the steps you would take to notify the telescope teams and begin observations.

Scenario 2:#

Context: You are on duty, and a telescope team has reported that they have started observations and uploaded images to the ownCloud.
Question: What do you include in SkyPortal comments?

Scenario 3:#

Context: After initial observations, a transient candidate is identified by an external team. An object is found in the images.
Question: Do we send a GCN report or wait for the analysis? If yes, what is included? If not, what is preventing you?

Section 13.4: Scenarios Part II#

Scenario 1: GW Candidate S230621ab#

Context: You receive an alert for GW candidate S230621ab during your shift. The alert arrives at 02:30 UTC and is detected by three interferometers.

Alert Review:#

  1. What is the first thing you should do after receiving the alert?

  2. How can you determine whether this event is astrophysical or noise?

Event Classification:#

  1. The event is classified as BBH. What does this mean for potential electromagnetic (EM) follow-up?

  2. Should this event be considered high-profile? What factors would lead you to that conclusion?

Sky Localization:#

  1. The 90% credible region of the sky localization area is 500 deg². How does this affect the observation strategy?

  2. If the event’s distance is 150 Mpc with an error of ±20 Mpc, how does that influence your decision to notify telescope teams?

Action Plan:#

  1. Based on the information available, should you instruct the telescope teams to begin observations? Why or why not?

Scenario 2: GW Candidate S230708kl#

Context: It’s the middle of your shift, and you receive a new alert for GW candidate S230708kl. The event is detected by two interferometers and is classified as BNS.

Alert Review:#

  1. The alert arrives at 10:45 UTC. Is it a fresh alert, and how can you determine if it is the first message for this alert within GRANDMA?

Event Classification:#

  1. The event is classified as BNS, and the distance is 180 Mpc with an error of ±10 Mpc. How does this classification affect your decision-making?

  2. Why is the detection of a neutron star in this binary system significant for GRANDMA?

Sky Localization:#

  1. The 50% credible region of the skymap is 100 deg², and the 90% credible region is 400 deg². How should you prioritize telescopes with smaller fields of view?

Action Plan:#

  1. Given the event’s proximity and classification, should you mark it as high-profile? If so, what are the next steps in coordinating observations?

  2. How should you communicate with the telescope teams, considering some are currently in daytime and cannot observe immediately?

Scenario 3: GW Candidate S230816yz#

Context: A new alert for GW candidate S230816yz arrives during your shift. It is classified as NSBH and detected by several interferometers. The event’s distance is 90 Mpc with an error of ±5 Mpc.

Alert Review:#

  1. Upon receiving the alert, what should your immediate actions be to confirm its importance?

  2. How can you verify that the alert has been communicated to the relevant teams in GRANDMA?

Event Classification:#

  1. The event is classified as NSBH. What does this mean for potential electromagnetic counterparts, and how does that affect GRANDMA’s strategy?

Sky Localization:#

  1. The 90% credible region of the skymap is 150 deg². How would you approach coordinating observations with telescope teams that have wide-field capabilities versus those with narrower fields of view?

Action Plan:#

  1. Given the small error in distance and the classification of the event, should this event be marked as high-profile? Justify your answer.

  2. Observations have been made, and images have been uploaded. Only one of the images has identified a candidate. Do you release a GCN? If yes, what do you include in the GCN? If not, what would prevent you from releasing a GCN?

Scenario 4: GW Candidate S231003xy#

Context: You receive an alert for GW candidate S231003xy during the final hour of your shift. The event is detected by three interferometers, and the alert classifies it as a BBH with a distance of 300 Mpc ±50 Mpc.

Alert Review:#

  1. How would you assess the priority of this event given its classification and distance?

  2. Should you notify telescope teams to observe this event? Explain your reasoning.

Event Classification:#

  1. Given that BBH events generally do not produce electromagnetic counterparts, under what circumstances would you still consider a follow-up?

Sky Localization:#

  1. The skymap shows that the 90% credible region covers 600 deg². How does this affect the feasibility of rapid follow-up observations?

Action Plan:#

  1. Observations have been made, and three telescopes have observed and uploaded images. No candidate has been found. Do you release a GCN? If yes, what do you include in the GCN? If not, what would prevent you from releasing a GCN?

  2. As your shift is ending soon, how should you transition this alert to the next FA on shift? What details are most important to pass along?

Scenario 5: GW Candidate S231020gh (False Alarm)#

Context: During your shift, you receive an alert for GW candidate S231020gh, detected by only one interferometer. Shortly after, you receive an update indicating that the event is likely a false alarm.

Alert Review:#

  1. What should be your immediate actions upon receiving the initial alert?

  2. How do you verify that the alert has been flagged as a false alarm, and what steps should you take to communicate this to the telescope teams?

Event Classification:#

  1. If the event had not been flagged as a false alarm, what criteria would you have used to assess its significance?

Sky Localization:#

  1. The initial skymap indicated a large uncertainty in localization. How does this influence your decision-making process for follow-up observations?

Action Plan:#

  1. How do you document the false alarm and ensure that all relevant teams are informed to avoid unnecessary observations?

  2. How should you transition this case to the next FA on shift, ensuring that no further follow-up is conducted?

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