[Paper Review] The Herschel Virgo Cluster Survey: II. Truncated dust disks in HI-deficient spirals

L. Cortese, J. I. Davies+28 more|arXiv (Cornell University)|May 17, 2010

Galaxies: Formation, Evolution, PhenomenaPhysics and Astronomy31 references85 citations

TL;DR

This study uses Herschel-SPIRE and 21 cm H i data to show that dust disks in HI-deficient spiral galaxies in the Virgo Cluster are significantly truncated, mirroring the truncation of their H i disks. The findings reveal that dust is stripped alongside gas in cluster environments, particularly in galaxies with high HI-deficiency, indicating environmental stripping as a key mechanism for enriching the intra-cluster medium with dust and metals.

ABSTRACT

By combining Herschel-SPIRE observations obtained as part of the Herschel Virgo Cluster Survey with 21 cm HI data from the literature, we investigate the role of the cluster environment on the dust content of Virgo spiral galaxies.We show for the first time that the extent of the dust disk is significantly reduced in HI-deficient galaxies, following remarkably well the observed 'truncation' of the HI disk. The ratio of the submillimetre-to- optical diameter correlates with the HI-deficiency, suggesting that the cluster environment is able to strip dust as well as gas. These results provide important insights not only into the evolution of cluster galaxies but also into the metal enrichment of the intra-cluster medium.

Motivation & Objective

• To investigate the impact of the cluster environment on the dust content of spiral galaxies in the Virgo Cluster.
• To determine whether HI-deficient galaxies—those with reduced atomic hydrogen—also exhibit reduced dust content.
• To examine the spatial extent of dust disks in relation to H i disk truncation and HI-deficiency.
• To assess whether environmental processes like ram pressure stripping affect dust distribution and mass in cluster spirals.
• To explore the implications of dust stripping for the metal enrichment of the intra-cluster medium.

Proposed method

• Combining Herschel-SPIRE submillimeter observations (100–500 μm) with 21 cm H i line data from the literature.
• Measuring the submillimeter-to-optical diameter ratio to quantify dust disk extent relative to optical disks.
• Using the HI-deficiency parameter (def_HI) to classify galaxies based on their H i content relative to isolated spirals of the same type and size.
• Analyzing the f(250)/f(K) and f(500)/f(K) flux density ratios as tracers of dust mass relative to stellar mass.
• Applying Spearman rank correlation to assess the relationship between dust properties and HI-deficiency.
• Comparing results with prior studies (e.g., Contursi et al. 2001) to identify sample-dependent biases in dust content trends.

Experimental results

Research questions

• RQ1 Does the truncation of H i disks in Virgo cluster spirals correspond to a similar truncation in their dust disks?
• RQ2 Is there a measurable correlation between HI-deficiency and the extent or surface density of dust disks?
• RQ3 To what extent is dust stripped from galaxies in cluster environments, and does this correlate with gas stripping?
• RQ4 Are the submillimeter-to-K-band flux density ratios of HI-deficient galaxies significantly lower than those of normal spirals, indicating reduced dust mass?
• RQ5 What role does environmental stripping play in the metal enrichment of the intra-cluster medium via dust injection?

Key findings

• The dust disk extent in HI-deficient spirals is significantly reduced, closely following the truncation of the H i disk.
• The submillimeter-to-optical diameter ratio correlates with HI-deficiency, indicating that dust is stripped in tandem with gas.
• Highly HI-deficient galaxies show f(250)/f(K) and f(500)/f(K) flux density ratios that are 2–3 times lower than normal spirals, indicating a substantial loss of dust mass.
• The correlation between dust properties and HI-deficiency breaks down for def_HI < 0.87, suggesting that significant dust stripping only occurs in galaxies with extreme gas deficiency.
• The results imply that environmental stripping, particularly ram pressure, efficiently removes dust from the outer regions of spirals when gas is stripped well within the optical radius.
• These findings, combined with direct detections of stripped dust, support dust stripping as a major mechanism for enriching the intra-cluster medium with dust and metals.