Intensity-Corrected Herschel Observations of Nearby Isolated Low-Mass Clouds

Abstract

We present intensity-corrected Herschel maps at 100 um, 160 um, 250 um, 350 um, and 500 um for 56 isolated low-mass clouds. We determine the zero-point corrections for Herschel PACS and SPIRE maps from the Herschel Science Archive (HSA) using Planck data. Since these HSA maps are small, we cannot correct them using typical methods. Here, we introduce a technique to measure the zero-point corrections for small Herschel maps. We use radial profiles to identify offsets between the observed HSA intensities and the expected intensities from Planck. Most clouds have reliable offset measurements with this technique. In addition, we find that roughly half of the clouds have underestimated HSA-SPIRE intensities in their outer envelopes relative to Planck, even though the HSA-SPIRE maps were previously zero-point corrected. Using our technique, we produce corrected Herschel intensity maps for all 56 clouds and determine their line-of-sight average dust temperatures and optical depths from modified black body fits. The clouds have typical temperatures of ~ 14-20 K and optical depths of ~ 1e-5 - 1e-3. Across the whole sample, we find an anti-correlation between temperature and optical depth. We also find lower temperatures than what was measured in previous Herschel studies, which subtracted out a background level from their intensity maps to circumvent the zero-point correction. Accurate Herschel observations of clouds are key to obtain accurate density and temperature profiles. To make such future analyses possible, intensity-corrected maps for all 56 clouds are publicly available in the electronic version.

Accepted to ApJ, 35 pages, 15 figures, 4 Tables. Intensity-corrected FITS images and temperature/optical depths maps are available with the electronic version

References in corpus (27)

• Theory of Star Formation
• Gaia Data Release 1. Summary of the astrometric, photometric, and survey properties
• Cold Dark Clouds: The Initial Conditions for Star Formation
• A Spitzer Survey of Young Stellar Clusters within One Kiloparsec of the Sun: Cluster Core Extraction and Basic Structural Analysis
• Observing the gas temperature drop in the high-density nucleus of L 1544
• 2MASS wide field extinction maps - I. The Pipe nebula
• Herschel-Planck dust optical-depth and column-density maps: I. Method description and results for Orion
• A Large Catalog of Accurate Distances to Molecular Clouds from PS1 Photometry
• Depletion and low gas temperature in the L183 prestellar core : the N2H+ - N2D+ tool
• 2MASS wide field extinction maps: II. The Ophiuchus and the Lupus cloud complexe
• The dynamics of collapsing cores and star formation
• The Spitzer c2d Survey of Nearby Dense Cores: I: First Direct Detection of the Embedded Source in IRAM 04191+1522
• The Earliest Phases of Star formation observed with Herschel (EPoS): The dust temperature and density distributions of B68
• Modeling Thermal Dust Emission with Two Components: Application to the Planck HFI Maps
• The nature of the dense core population in the Pipe Nebula: A survey of NH3, CCS, and HC5N molecular line emission
• Spitzer Observations of Bok Globule B335: Isolated Star Formation Efficiency and Cloud Structure
• Chemistry and Radiative Transfer of Water in Cold, Dense Clouds
• The dust temperatures of the prestellar cores in the rho Oph main cloud and in other star forming regions: consequences for the core mass function
• The JCMT Gould Belt Survey: A First Look at Southern Orion A with SCUBA-2
• Oscillations of starless cores
• Large-scale magnetic fields in Bok globules
• A 2MASS Analysis of the Stability of Southern Bok Globules
• The Earliest Phases of Star formation (EPoS): Temperature, density, and kinematic structure of the star-forming core CB 17
• Distance estimation of some selected small Bok globules
• Constraining the Dust Opacity Law in Three Small and Isolated Molecular Clouds
• Study of grain alignment efficiency and a distance estimate for small globule CB4
• 3-D Kinematics of the near-IR HH 223 outflow in L723

Cited by in corpus (8)

• Astrochemical models of interstellar ices: History matters
• The link between gas and stars in the S254-S258 star-forming region
• The Twisted Magnetic Field of the Protobinary L483
• Constraints on the non-thermal desorption of methanol in the cold core LDN 429-C
• Simulations of the isothermal collapse of magnetic rotating protostellar clouds
• Twisted magnetic field in star formation processes of L1521 F revealed by submillimeter dual band polarimetry using James Clerk Maxwell Telescope
• Chemical constraints on the dynamical evolution of the cold core L694
• A Survey of Magnetic Field Properties in Bok Globules