Galactic Cirri at High Galactic Latitudes: I. Investigating Scatter in Slopes between Optical and far-Infrared Intensities

Abstract

Based on the slopes between DESI $g,r$ and IRAS 100 $\mu m$ intensities, specifically $k_g$ and $k_r$, we have constructed a substantial sample of Galactic cirri. This sample covers 561.25 deg${}^2$ at high Galactic latitudes (|b| $\ge$ 30${}^{\circ }$), allowing for a systematic study of the physical parameters of the Galactic cirrus on a large scale, such as $g-r$ color, dust temperature, asymmetry factor and albedo. The ratio of $k_g$ and $k_r$ is consistent with the diffuse Galactic starlight model, suggesting that the diffuse starlight within our own Galaxy serves as the primary illumination source for the cirrus. Both $k_g$ and $k_r$ decrease slowly with increasing Galactic latitudes and IRAS 100 $\mu m$ intensities, while they do not have a correlation with Galactic longitudes. The distribution of $k_g$ and $k_r$ confirms a significant scatter in the slopes, reaching a factor of 4-5. Such large scatter cannot be explained by the weak correlation between the slopes and Galactic latitudes and IRAS 100 $\mu m$ intensities. Instead, it is attributed to substantial variations in the intrinsic properties of the dust, e.g., asymmetry factor and albedo. We propose that the properties of dust particles play a critical role in the observed scatter in slopes, making them the primary contributing factors. Moreover, the variations in dust properties within the cirrus are localized rather than exhibiting large-scale gradients.

26 pages, 16 figures, 2 tables. Accepted for publication in AJ

References in corpus (10)

• The Burrell Schmidt Deep Virgo Survey: Tidal Debris, Galaxy Halos, and Diffuse Intracluster Light in the Virgo Cluster
• Extended Red Emission in High-Galactic Latitude Interstellar Clouds
• GALEX Diffuse Observations of the Sky: The Data
• Ultraviolet to optical diffuse sky emission as seen by the Hubble Space Telescope Faint Object Spectrograph
• The Herschel Virgo Cluster Survey. XX. Dust and gas in the foreground Galactic cirrus
• The GALEX Ultraviolet Virgo Cluster Survey (GUViCS). V. Ultraviolet diffuse emission and cirrus properties in the Virgo cluster direction
• A giant umbrella-like stellar stream around the tidal ring galaxy NGC 922
• Prospects for future studies using deep imaging: Analysis of individual Galactic cirrus filaments
• Galactic Latitude Dependence of Near-Infrared Diffuse Galactic Light : Thermal Emission or Scattered Light?
• A Mysterious Ring in Dark Space?

Cited by in corpus (3)

• Analysis of Galactic cirrus filaments in HSC-SSP high-resolution deep images using artificial neural networks
• Quantitative Morphology of Galactic Cirrus in Deep Optical Imaging
• Tidal Structures Around Edge-On Galaxies in Deep Imaging Surveys