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The analysis of the physical properties of low-redshift Ly alpha emitters (LAEs) can provide clues in the study of their high-redshift analogs. At z similar to 0.3, LAEs are bright enough to be detected over almost the entire electromagnetic spectrum and it is possible to carry out a more precise and complete study than at higher redshifts. In this work, we examine the UV and IR emission, dust attenuation, star formation rate (SFR), and morphology of a sample of 23 GALEX-discovered star-forming LAEs at z similar to 0.3 with direct UV (GALEX), optical (ACS), and FIR (PACS and MIPS) data. Using the same UV and IR limiting luminosities, we find that LAEs at z similar to 0.3 tend to be less dusty, have slightly higher total SFRs, have bluer UV continuum slopes, and are much smaller than other galaxies that do not exhibit Ly alpha emission in their spectrum (non-LAEs). These results suggest that at z similar to 0.3, Ly alpha photons tend to escape from small galaxies with low dust attenuation. Regarding their morphology, LAEs belong to Irr/merger classes, unlike non-LAEs. Size and morphology represent the most noticeable difference between LAEs and non-LAEs at z similar to 0.3. Furthermore, the comparison of our results with those obtained at higher redshifts indicates either that the Ly alpha technique picks up different kind of galaxies at different redshifts or that the physical properties of LAEs are evolving with redshift.

One remaining open question regarding the physical properties of Ly alpha emitters (LAEs) is their dust content and evolution with redshift. The variety of results is large and with those reported by now it is difficult to establish clear relations between dust, other fundamental parameters of galaxies (star formation rate, metallicity, or age), and redshift. In this Letter, we report Herschel PACS-100 mu m, PACS-160 mu m, and Spitzer MIPS-24 mu m detections of a sample of spectroscopically GALEX selected LAEs at z similar to 0.3 and similar to 1.0. Five out of ten and one out of two LAEs are detected in, at least, one PACS band at z similar to 0.3 and similar to 1.0, respectively. These measurements have a great importance given that they allow us to quantify, for the first time, the dust content in LAEs from direct FIR observations. MIPS-24 mu m detections allow us to determine the IR properties of the PACS-undetected LAEs. We obtain that mid-IR/FIR-detected star-forming (SF) LAEs at z similar to 0.3 have dust content within 0.75 less than or similar to A(1200 angstrom) less than or similar to 2.0, with a median value of A(1200 angstrom) similar to 1.1. This range broadens up to 0.75 less than or similar to A(1200 angstrom) less than or similar to 2.5 when considering the LAEs at z similar to 1.0. Only one SF LAE is undetected both in MIPS-24 mu m and PACS, with A(1200 angstrom) less than or similar to 0.75. These results seem to be larger than those reported for high-redshift LAEs and, therefore, although an evolutionary trend is not clearly seen, it could point out that low-redshift LAEs are dustier than high-redshift ones. However, the diverse methods used could introduce a systematic offset in the results.