Peering into the Milky Way by FAST: I. Exquisite HI structures in the inner Galactic disk from the piggyback line observations of the FAST GPPS survey

Abstract

Neutral hydrogen (HI) is the fundamental component of the interstellar medium. The Galactic Plane Pulsar Snapshot (GPPS) survey is designed for hunting pulsars by using the Five-hundred-meter Aperture Spherical radio Telescope (FAST) from the visible Galactic plane within $|b|\le 10^{\circ }$. The survey observations are conducted with the L-band 19-beam receiver in the frequency range of 1.0 $-$ 1.5 GHz, and each pointing has an integration time of 5 minutes. The piggyback spectral data simultaneously recorded during the FAST GPPS survey are great resources for studies on the Galactic HI distribution and ionized gas. We process the piggyback HI data of the FAST GPPS survey in the region of $33^{\circ }\le l\le 55^{\circ }$ and $|b|\le 2^{\circ }$. The rms of the data cube is found to be approximately 40 mK at a velocity resolution of $0.1$ km s${}^{-1}$, placing it the most sensitive observations of the Galactic HI by far. The high velocity resolution and high sensitivity of the FAST GPPS HI data enable us to detect weak exquisite HI structures in the interstellar medium. HI absorption line with great details can be obtained against bright continuum sources. The FAST GPPS survey piggyback HI data cube will be released and updated on the web: http://zmtt.bao.ac.cn/MilkyWayFAST/.

arXiv commentPublished by ScienceChinaPMA on the special topic "Peering into the Milky Way by FAST" https://www.sciengine.com/SCPMA/issue/65/12 . See News & Views by Prof. John M. Dickey https://link.springer.com/content/pdf/10.1007/s11433-022-2030-x.pdf

References in corpus (36)

• The Leiden/Argentine/Bonn (LAB) Survey of Galactic HI: Final data release of the combined LDS and IAR surveys with improved stray-radiation corrections
• HI4PI: A full-sky HI survey based on EBHIS and GASS
• Trigonometric Parallaxes of High Mass Star Forming Regions: the Structure and Kinematics of the Milky Way
• The Five-Hundred-Meter Aperture Spherical Radio Telescope (FAST) Project
• The VLA Galactic Plane Survey
• The WISE Catalog of Galactic HII Regions
• The Southern Galactic Plane Survey: HI Observations and Analysis
• GASS: The Parkes Galactic All-Sky Survey. I. Survey Description, Goals, and Initial Data Release
• The Fundamental Performance of FAST with 19-beam Receiver at L Band
• The GALFA-HI Survey: Data Release 1
• The Spiral Structure of the Outer Milky Way in Hydrogen
• GASS: The Parkes Galactic All-Sky Survey. II. Stray-Radiation Correction and Second Data Release
• The Effelsberg-Bonn HI Survey: Milky Way gas. First data release
• The FAST Galactic Plane Pulsar Snapshot survey: I. Project design and pulsar discoveries
• HI Narrow Line Absorption in Dark Clouds
• GASS: The Parkes Galactic All-Sky Survey. Update: improved correction for instrumental effects and new data release
• Galactic Supernova Remnant Candidates Discovered by THOR
• GASKAP -- The Galactic ASKAP Survey
• A Self-Absorption Census of Cold HI Clouds in the Canadian Galactic Plane Survey
• Cold Milky Way Hi gas in filaments
• New Distances to Four Supernova Remnants
• Revised Distances to 21 Supernova Remnants
• The Distances of SNRs Kes 69 and G21.5-0.9 from HI and 13CO Spectra
• The HI/OH/Recombination line survey of the inner Milky Way (THOR): data release 2 and HI overview
• Tracing the Spiral Structure of the Outer Milky Way with Dense Atomic Hydrogen Gas
• GASKAP-HI Pilot Survey Science I: ASKAP Zoom Observations of HI Emission in the Small Magellanic Cloud
• The history of dynamics and stellar feedback revealed by the HI filamentary structure in the disk of the Milky Way
• The Galactic dynamics revealed by the filamentary structure in atomic hydrogen emission
• Radio Frequency Interference Mitigation based on the ArPLS and SumThreshold Method
• GASKAP Pilot Survey Science II: ASKAP Zoom Observations of Galactic 21-cm Absorption
• Peering into the Milky Way by FAST: II. Ionized gas in the inner Galactic disk revealed by the piggyback line observations of the FAST GPPS survey
• Peering into the Milky Way by FAST: IV. Identification of two new Galactic supernova remnants G203.1+6.6 and G206.7+5.9
• Pilot HI Survey of Planck Galactic Cold Clumps with FAST
• Peering into the Milky Way by FAST: III. Magnetic fields in the Galactic halo and farther spiral arms revealed by the Faraday effect of faint pulsars
• The discovery of the largest gas filament in our Galaxy, or a new spiral arm?
• A FAST Survey of HINSA in PGCCs Guided by HC3N

Cited by in corpus (9)

• The FAST Galactic Plane Pulsar Snapshot survey: VI. The discovery of 473 new pulsars
• Peering into the Milky Way by FAST: II. Ionized gas in the inner Galactic disk revealed by the piggyback line observations of the FAST GPPS survey
• Peering into the Milky Way by FAST: IV. Identification of two new Galactic supernova remnants G203.1+6.6 and G206.7+5.9
• Distance of PSR B0458+46 indicated by FAST HI absorption observations
• Peering into the Milky Way by FAST: III. Magnetic fields in the Galactic halo and farther spiral arms revealed by the Faraday effect of faint pulsars
• HI Absorption in Low-power Radio AGNs Detected by FAST
• Insights into the structure and kinematics of a Milky Way-like galaxy
• Constraints on the properties of warm ionized gas from low-frequency hydrogen radio recombination lines
• Accurate polarization calibration of FAST spectral data for measurements of Zeeman splittings of OH megamasers in IRAS 02524+2046