Cardiff University | Prifysgol Caerdydd ORCA
Online Research @ Cardiff 
WelshClear Cookie - decide language by browser settings

The HASHTAG project: The first submillimeter images of the Andromeda Galaxy from the ground.

Smith, M. W. L., Eales, S. A., Williams, T. G., Lee, B., Li, Z., Barmby, P., Bureau, M., Chapman, S., Brian, C. S., Chung, A., Chung, E. J., Chung, H., Clark, C. J. R., Clements, D. L., Davis, T. A., De Looze, I., Eden, D. J., Athikkat Eknath, Gayathri, Ford, G. P., Gao, Y., Gear, W., Gomez, H. L., De Grijs, R., He, J., Ho, L.C., Hughes, T. M., Jiao, S., Li, Z., Kemper, F., Kirchschlager, F., Koch, E. W., Kong, A. K. H., Lee, C., Lin, E., Mairs, S., Michalowski, M. J., Pattle, K., Peng, Y., Ragan, S. E., Rawlings, M. G., Rigopoulou, D., Saintonge, A., Schruba, A., Tang, X., Wang, J., Whitworth, A. P., Wilson, C. D., Yim, K. and Zhu, M. 2021. The HASHTAG project: The first submillimeter images of the Andromeda Galaxy from the ground. Astrophysical Journal Supplement Series 257 , 52. 10.3847/1538-4365/ac23d0
Item availability restricted.

[thumbnail of hashtag.pdf] PDF - Accepted Post-Print Version
Restricted to Repository staff only until 1 December 2022 due to copyright restrictions.

Download (5MB)


Observing nearby galaxies with submillimeter telescopes on the ground has two major challenges. First, the brightness is significantly reduced at long submillimeter wavelengths compared to the bright- ness at the peak of the dust emission. Second, it is necessary to use a high-pass spatial filter to remove atmospheric noise on large angular scales, which has the unwelcome by-product of also removing the galaxy’s large-scale structure. We have developed a technique for producing high-resolution submillimeter images of galaxies of large angular size by using the telescope on the ground to determine the small-scale structure (the large Fourier components) and a space telescope (Herschel or Planck) to determine the large-scale structure (the small Fourier components). Using this technique, we are carrying out the HARP and SCUBA-2 High Resolution Terahertz Andromeda Galaxy Survey (HASHTAG), an international Large Program on the James Clerk Maxwell Telescope, with one aim being to produce the first high-fidelity high-resolution submillimeter images of Andromeda. In this paper, we describe the survey, the method we have developed for combining the space-based and ground-based data, and present the first HASHTAG images of Andromeda at 450 and 850 μm. We also have created a method to predict the CO(J=3–2) line flux across M31, which contaminates the 850μm band. We find that while normally the contamination is below our sensitivity limit, the contamination can be significant (up to 28%) in a few of the brightest regions of the 10 kpc ring. We therefore also provide images with the predicted line emission removed.

Item Type: Article
Date Type: Publication
Status: Published
Schools: Physics and Astronomy
Date of First Compliant Deposit: 16 December 2021
Date of Acceptance: 3 September 2021
Last Modified: 31 Jan 2022 16:55

Actions (repository staff only)

Edit Item Edit Item


Downloads per month over past year

View more statistics