Find the entry of this object in the
ALFALFA archive, and use the
images and links there to find the answers to these questions. As always, it is most important
that you understand how to derive quantitative answers and their uncertainties.
- Compute the HI mass of the galaxy. Do you get the same answer as the value given
in the ALFALFA database?
- Examine carefully the catalogued HI parameters given in the database this galaxy.
What do you notice about the appearance of the HI spectrum that seems inconsistent?
- Take a look at the nearby ALFALFA source
How far apart are the positions of the two ALFALFA sources on the sky? How does this compare to the
size of the ALFA beam?
- What is the linear separation if the sources lie
the Virgo distance of 16.7 Mpc?
- How can you understand the unusual circumstance you noted in 2. above?
- Check out the ALFALFA map of Virgo HI21.