The Parkes HI survey of the Magellanic System

By C. Bruens, J. Kerp, L. Staveley-Smith, U. Mebold, M. Putman, R. Haynes, P. Kalberla, E. Muller, M. Institut, U. Bonn and 5 more. 2004

193 citations recorded by the source corpus.

We present the first fully and uniformly sampled, spatially complete $\ion{H}{i}$ survey of the entire Magellanic System with high velocity resolution ($\Delta v = 1.0$ km s -1 ), performed with the Parkes Telescope. Approximately 24 percent of the southern sky was covered by this survey on a ≈ 5´ grid with an angular resolution of ${\it HPBW} = 14\farcm1$. A fully automated data-reduction scheme was developed for this survey to handle the large number of $\ion{H}{i}$ spectra ($1.5\times10^6$). The individual Hanning smoothed and polarization averaged spectra have an rms brightness temperature noise of σ = 0.12 K. The final data-cubes have an rms noise of $\sigma_{\rm rms} \approx 0.05$ K and an effective angular resolution of ≈ 16´. In this paper we describe the survey parameters, the data-reduction and the general distribution of the $\ion{H}{i}$ gas. The Large Magellanic Cloud (LMC) and the Small Magellanic Cloud (SMC) are associated with huge gaseous features – the Magellanic Bridge, the Interface Region, the Magellanic Stream, and the Leading Arm – with a total $\ion{H}{i}$ mass of M ($\ion{H}{i}$) = $4.87\times10^8~M_\odot \left[d/55~{\rm kpc}\right]^2$, if all $\ion{H}{i}$ gas is at the same distance of 55 kpc. Approximately two thirds of this $\ion{H}{i}$ gas is located close to the Magellanic Clouds (Magellanic Bridge and Interface Region), and 25% of the $\ion{H}{i}$ gas is associated with the Magellanic Stream. The Leading Arm has a four times lower $\ion{H}{i}$ mass than the Magellanic Stream, corresponding to 6% of the total $\ion{H}{i}$ mass of the gaseous features. We have analyzed the velocity field of the Magellanic Clouds and their neighborhood introducing a LMC-standard-of-rest frame. The $\ion{H}{i}$ in the Magellanic Bridge shows low velocities relative to the Magellanic Clouds suggesting an almost parallel motion, while the gas in the Interface Region has significantly higher relative velocities indicating that this gas is leaving the Magellanic Bridge building up a new section of the Magellanic Stream. The Leading Arm is connected to the Magellanic Bridge close to an extended arm of the LMC. The clouds in the Magellanic Stream and the Leading Arm show significant differences, both in the column density distribution and in the shapes of the line profiles. The $\ion{H}{i}$ gas in the Magellanic Stream is more smoothly distributed than the gas in the Leading Arm. These morphological differences can be explained if the Leading Arm is at considerably lower z -heights and embedded in a higher pressure ambient medium.

Subfields: Astronomy and Astrophysics

View Paper: https://www.semanticscholar.org/paper/ba517316cdad0dfc2e0b6708dedeca8b14755e6c

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Astronomy and Astrophysics

Citations in the corpus

The Proper Motion of the Large Magellanic Cloud Using HST (2005, background): “The Magellanic Stream is an H i emission feature that spans more than 100 across the sky (Brüns et al. 2005).”
The VPOS: a vast polar structure of satellite galaxies, globular clusters and streams around the Milky Way (2012, background): “The angular distance from the DoS normal vector is Θ. References: (1) Brüns et al. (2005); (2) Grillmair (2006b); (3) Grillmair (2009); (4) Grillmair & Dionatos (2006a); (5) Grillmair & Dionatos (2006b); (6) Grillmair & Johnson (2006); (7) Jin (2010); (8) Lauchner et al. (2006); (9) Majewski et…”
GASS: THE PARKES GALACTIC ALL-SKY SURVEY. I. SURVEY DESCRIPTION, GOALS, AND INITIAL DATA RELEASE (2009, methodology): “The peak of the observed line was used to calculate calibration scaling factors for each beam and each polarization assuming peak brightness temperatures of TB = 83 K for S9, TB = 53 K for S6 and TB = 76 K for S8 valid for the Parkes beam (Kalberla et al. 1982; Brüns et al. 2005).”
Are the Magellanic Clouds on Their First Passage about the Milky Way? (2007, background): “The tidal strippingmodel of Connors et al. (2006) is the only work to date to account for the recent Brüns et al. (2005) H i Parkes All Sky Survey results; however, their orbital velocities are inconsistent with the new proper motions (this is true irrespective of the halo model).”
The H i Distribution of the Milky Way (2009, background): “The “rims” of the HVCs with distances of at least a few kiloparsecs are not characterized by sharp cut-offs of the column density distribution at a certain column density threshold, as shown, e.g., by Brüns et al. (2005) for the Magellanic Stream and Leading Arm.”
Multiphase High-Velocity Clouds toward HE 0226–4110 and PG 0953+414 (2005, background): “TheMagellanic Stream is a broad filament of material covering 1000 deg2 in an arc extending from l 90 , b 45 , through the south Galactic pole and around to positive latitudes (Putman et al. 2003b; Brüns et al. 2005).”
THIRD-EPOCH MAGELLANIC CLOUD PROPER MOTIONS. I. HUBBLE SPACE TELESCOPE/WFC3 DATA AND ORBIT IMPLICATIONS (2013, background): “…attention from the community in part because they require a new formation mechanism for the Magellanic Stream, a young coherent stream of H I gas that trails the Clouds ∼ 150◦ across the sky (Wannier & Wrixon 1972; Mathewson et al. 1974; Putman et al. 2003; Brüns et al. 2005; Nidever et al. 2010).”
The Origin of the Magellanic Stream and Its Leading Arm (2007, unknown): “Surveys have been made in H I emission at 21-cm (HIPASS: Barnes et al. 2001; Brüns et al. 2005; Staveley-Smith et al. 1997, 2003; Stanimirović et al. 1999; and Muller et al. 2003), in molecular spectral CO lines (NANTEN: Fukui et al. 1999; Mizuno et al. 2001), as well as in the radio continuum…”
The gravitational and hydrodynamical interaction between the Large Magellanic Cloud and the Galaxy (2004, methodology): “In order to take into account the loss of cold gas from the disc of the satellite, we assumed an initial amount of gas in the disc that is ∼2–3 times larger than H I observed to be associated with the LMC (Kim et al. 1998; Putman et al. 2003a; Brüns et al. 2005).”
The role of dwarf galaxy interactions in shaping the Magellanic System and implications for Magellanic Irregulars (2012, methodology): “(1) van der Marel et al. (2002): the outermost data point lies at 9 kpc; (2) Brüns et al. (2005); (3) van der Marel, Kallivayalil & Besla (2009); (4) Kim et al. (1998); (5) Stanimirović et al. (2004); (6) Harris & Zaritsky (2006); (7) here we have accounted for the average distance to the…”