Podcast
Questions and Answers
What is the primary use of the He II λ4686 Å line in planetary nebulae?
What is the primary use of the He II λ4686 Å line in planetary nebulae?
- To estimate the distance to the nebula
- To measure the temperature of the central star (CS)
- To determine the elemental abundances within the nebula
- To quantify the nebular excitation class (EC) (correct)
What is the minimum effective temperature required for the presence of the He II λ4686 Å line?
What is the minimum effective temperature required for the presence of the He II λ4686 Å line?
- 85 000 K (correct)
- 50 000 K
- 70 000 K
- 60 000 K
Which of the following parameters does NOT influence the excitation class of a planetary nebula?
Which of the following parameters does NOT influence the excitation class of a planetary nebula?
- Elemental abundances
- Central star temperature
- Nebular excitation level
- Distance to the nebula (correct)
What is the range of excitation class (EC) where the He II λ4686 Å line is absent?
What is the range of excitation class (EC) where the He II λ4686 Å line is absent?
What is the purpose of equations (1) and (2) in Reid & Parker's (2010) classification scheme?
What is the purpose of equations (1) and (2) in Reid & Parker's (2010) classification scheme?
How many classification schemes for the EC are mentioned in the text?
How many classification schemes for the EC are mentioned in the text?
What is the relationship between the [O III]/Hβ line ratio and EC ≥ 5?
What is the relationship between the [O III]/Hβ line ratio and EC ≥ 5?
Which of the following is NOT a parameter that influences the EC of a planetary nebula?
Which of the following is NOT a parameter that influences the EC of a planetary nebula?
What is the purpose of the He II λ4686 Å line in Reid & Parker's (2010) classification scheme?
What is the purpose of the He II λ4686 Å line in Reid & Parker's (2010) classification scheme?
What is the primary factor that determines the excitation level of a planetary nebula?
What is the primary factor that determines the excitation level of a planetary nebula?
