%0 Generic %1 yang2016lyalpha %A Yang, Huan %A Malhotra, Sangeeta %A Rhoads, James E. %A Leitherer, Claus %A Wofford, Aida %A Jiang, Tianxing %A Wang, Junxian %D 2016 %K Lya UV size %T Ly$\alpha$ and UV Sizes of Green Pea Galaxies %U http://arxiv.org/abs/1610.05767 %X Green Peas are nearby analogs of high-redshift Ly$\alpha$-emitting galaxies. To probe their Ly$\alpha$ escape, we study the spatial profiles of Ly$\alpha$ and UV continuum emission of 24 Green Pea galaxies using the Cosmic Origins Spectrograph (COS) on Hubble Space Telescope (HST). We extract the spatial profiles of Ly$\alpha$ emission from their 2D COS spectra, and of UV continuum from both the 2D spectra and NUV images. The Ly$\alpha$ emission shows more extended spatial profiles than the UV continuum in most Green Peas. The deconvolved Full Width Half Maximum (FWHM) of the Ly$\alpha$ spatial profile is about 2 to 4 times that of the UV continuum in most cases. The Ly$\alpha$ light shows significant offsets from the UV continuum in four galaxies and central absorption in one galaxy. We also compare the spatial profiles of Ly$\alpha$ photons at blueshifted and redshifted velocities in eight Green Peas with sufficient data quality, and find the blue wing of the Ly$\alpha$ line has a larger spatial extent than the red wing in four Green Peas with comparatively weak blue Ly$\alpha$ line wings. These results together indicate that most Ly$\alpha$ photons escape out of Ly$\alpha$-emitting galaxies through many resonant scatterings in the HI gas. Five Lyman continuum (LyC) leakers in this sample have similar Ly$\alpha$ to UV continuum size ratios ($\sim1.4-4.3$) to the other Green Peas, indicating their LyC emission escape through ionized holes in the interstellar medium.

@misc{yang2016lyalpha, abstract = {Green Peas are nearby analogs of high-redshift Ly$\alpha$-emitting galaxies. To probe their Ly$\alpha$ escape, we study the spatial profiles of Ly$\alpha$ and UV continuum emission of 24 Green Pea galaxies using the Cosmic Origins Spectrograph (COS) on Hubble Space Telescope (HST). We extract the spatial profiles of Ly$\alpha$ emission from their 2D COS spectra, and of UV continuum from both the 2D spectra and NUV images. The Ly$\alpha$ emission shows more extended spatial profiles than the UV continuum in most Green Peas. The deconvolved Full Width Half Maximum (FWHM) of the Ly$\alpha$ spatial profile is about 2 to 4 times that of the UV continuum in most cases. The Ly$\alpha$ light shows significant offsets from the UV continuum in four galaxies and central absorption in one galaxy. We also compare the spatial profiles of Ly$\alpha$ photons at blueshifted and redshifted velocities in eight Green Peas with sufficient data quality, and find the blue wing of the Ly$\alpha$ line has a larger spatial extent than the red wing in four Green Peas with comparatively weak blue Ly$\alpha$ line wings. These results together indicate that most Ly$\alpha$ photons escape out of Ly$\alpha$-emitting galaxies through many resonant scatterings in the HI gas. Five Lyman continuum (LyC) leakers in this sample have similar Ly$\alpha$ to UV continuum size ratios ($\sim1.4-4.3$) to the other Green Peas, indicating their LyC emission escape through ionized holes in the interstellar medium.}, added-at = {2016-10-20T09:56:29.000+0200}, author = {Yang, Huan and Malhotra, Sangeeta and Rhoads, James E. and Leitherer, Claus and Wofford, Aida and Jiang, Tianxing and Wang, Junxian}, biburl = {https://www.bibsonomy.org/bibtex/2480e7b7ff389b83db95295b5120801b6/miki}, description = {[1610.05767] Ly$\alpha$ and UV Sizes of Green Pea Galaxies}, interhash = {afd6faf36c7392196b47249dcc60aae6}, intrahash = {480e7b7ff389b83db95295b5120801b6}, keywords = {Lya UV size}, note = {cite arxiv:1610.05767Comment: 7 pages, 5 figures. Submitted to ApJ}, timestamp = {2016-10-20T09:56:29.000+0200}, title = {Ly$\alpha$ and UV Sizes of Green Pea Galaxies}, url = {http://arxiv.org/abs/1610.05767}, year = 2016 }