Herschel Schedule

CASCA 2013 Schedule for Herschel

Location: Hennings 202 Chair: Gaelen Marsden
1600 Matthews, Brenda Impact of the Herschel Key Program DEBRIS
  The Herschel open time key program DEBRIS (Disk Emission via a Bias-free Reconnaissance in the Infrared/Submillimetre) was the only such program led in Canada. The goal of the survey was to detect debris disks with unprecedented sensitivity, spectral coverage and resolution toward 446 of the nearest stars via excess emission. The targets were unbiased to any stellar characteristic but fill different volumes for spectral types A0 through M7 in order to have ~90 targets in each spectral bin. With all the data in hand, it is clear that Herschel lasting legacy will be in the resolution if debris disk systems; of the 70+ detected debris disks, an overall incidence of 17%, half of the disks are resolved. The DEBRIS data also reveal an increased likelihood of debris associated with low-mass planetary systems, in contrast to findings for high-mass planets which are typically devoid of debris. This correlation was made possible by the recent discovery of planets in the systems, revealing the strength of the unbiased approach in such a survey.
1615 Tahani, Kianoosh * Orion-S star formation region latest update
  We will present initial results from a spectral survey toward Orion-S, taken by the HIFI instrument aboard the Herschel space telescope, in which we detect more than 800 spectral lines with S/N > 3 sigma originating from 47 different molecular and atomic species as well as a number of unidentified lines. Focusing on the transitions with S/N > 5 sigma we fit Gaussian line profiles to each of the observed transitions and have performed rotation/population diagram analysis for all the species for which we observed multiple transitions. This analysis provides us with the physical conditions, shows the presence of both warm (100 K) and cold (30 K) regions. A combination of population diagram analysis and the actual Local Thermodynamic Equilibrium modeling of the line profiles make us confident in the results of the molecular abundances, temperature, and other physical conditions in these two regions.
1630 Parkin, Tara * Heating and Cooling Variations in M51
  I present new spectroscopy from the PACS instrument on the Herschel Space Observatory of the grand design spiral galaxy, M51. These spectra focus on the atomic fine structure lines [CII](158 microns), [NII](122 microns), [OI](63 and 145 microns), and [OIII](88 microns), which are important cooling lines of the interstellar medium (ISM). We combine these data with previously published Herschel PACS photometry at 70 and 160 microns, as well as Spitzer Space Observatory MIPS photometry at 24 microns to explore some of the physical characteristics of the instellar gas of M51 on a pixel-by-pixel scale. We consider four different regions within M51, the nucleus, centre, arm and interarm regions to look for variations between these different environments. We compare our observations to a photodissociation region model to determine the density, far-ultraviolet radiation field and gas temperature in each region, and find that despite the arm and interarm regions consisting of differing star-formation rate surface densities, the properties of the gas are the same within the limits of the model. This is the first study that has resolved differences between environments on local scales within M51.
1645 Asboth, Viktoria * Finding very high redshift starburst galaxies with Herschel
  We report on a HerMES program using the SPIRE instrument on the Herschel Space Observatory to discover sources with extremely red submillimeter colours. These objects are expected to be dusty starburst galaxies at redshifts z>3 based on the shape of their spectral energy distributions. Follow-up observations of a sample of these objects confirm that at least some these sources are indeed at very high redshift. One of these objects, the recently discovered HFLS3 at z=6.34 is the highest redshift starburst galaxy known to date. It has a star formation rate of 2900 solar masses per year. Evolution models predict that the star formation rate of the Universe peaks around redshift z~2, and the distribution of submillimeter selected starburst galaxies peaks at z ~2 to 3. Finding very massive and actively star forming galaxies like HFLS3 at high redshifts poses a challenge for galaxy evolution models, suggesting that some galaxies form their stars in massive starbursts earlier than predicted. We have demonstrated that these sources do exist; to investigate the statistical properties and redshift distribution of this population a larger sample would be needed. I will talk about a ongoing search of these objects on a larger area field and about the observed properties of these sources.