TY - JOUR
T1 - A tale of two tails
T2 - Exploring stellar populations in the tidal tails of NGC 3256
AU - Rodruck, Michael
AU - Konstantopoulos, Iraklis
AU - Knierman, Karen
AU - Fedotov, Konstantin
AU - Mullan, Brendan
AU - Gallagher, Sarah
AU - Durrell, Patrick
AU - Ciardullo, Robin
AU - Gronwall, Caryl
AU - Charlton, Jane
N1 - Funding Information:
ACKNOWLEDGEMENTS We would like to thank the anonymous referee for helpful comments which have improved the quality and content of this paper. This paper is based on observations obtained at the GeminiObservatory (programme ID GS-2013A-Q-57, processed using the Gemini IRAF package), which is operated by the Association of Universities for Research in Astronomy, Inc., under a cooperative agreement with the NSF on behalf of the Gemini partnership: the National Science Foundation (United States), the National Research Council (Canada), CONICYT (Chile), Ministerio de Ciencia, Tecnología e Innovación Productiva (Argentina) and Ministério da Ciência, Tecnologia e Inovação (Brazil). The Digitized Sky Surveys were produced at the Space Telescope Science Institute under US Government grant NAGW-2166. The images of these surveys are based on photographic data obtained using the Oschin Schmidt Telescope on Palomar Mountain and the UK Schmidt Telescope. The plates were processed into the present compressed digital form with the permission of these institutions. SCG thanks the Natural Science and Engineering Research Council of Canada for support. KK is supported by an NSF Astronomy and Astrophysics Postdoctoral Fellowship under award AST-1501294. The Institute for Gravitation and the Cosmos is supported by the Eberly College of Science and the Office of the Senior Vice President for Research at the Pennsylvania State University.
Publisher Copyright:
© 2016 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society.
PY - 2016/9/1
Y1 - 2016/9/1
N2 - We have developed an observing programme using deep, multiband imaging to probe the chaotic regions of tidal tails in search of an underlying stellar population, using NGC 3256's 400 Myr twin tidal tails as a case study. These tails have different colours of u - g = 1.05 ± 0.07 and r - i = 0.13 ± 0.07 for NGC 3256W, and u - g = 1.26 ± 0.07 and r - i = 0.26 ± 0.07 for NGC 3256E, indicating different stellar populations. These colours correspond to simple stellar population ages of 288-54+11 and 841-157+125 Myr for NGC 3256W and NGC 3256E, respectively, suggesting that NGC 3256W's diffuse light is dominated by stars formed after the interaction, while light in NGC 3256E is primarily from stars that originated in the host galaxy. Using a mixed stellar population model, we break our diffuse light into two populations: one at 10 Gyr, representing stars pulled from the host galaxies, and a younger component, whose age is determined by fitting the model to the data. We find similar ages for the young populations of both tails (195+0-13 and 170+44-70 Myr for NGC 3256W and NGC 3256E, respectively), but a larger percentage of mass in the 10 Gyr population for NGC 3256E (98-3+1 per cent versus 90-6+5 per cent). Additionally, we detect 31 star cluster candidates in NGC 3256W and 19 in NGC 2356E, with median ages of 141 and 91 Myr, respectively. NGC 3256E contains several young (<10 Myr), low-mass objects with strong nebular emission, indicating a small, recent burst of star formation.
AB - We have developed an observing programme using deep, multiband imaging to probe the chaotic regions of tidal tails in search of an underlying stellar population, using NGC 3256's 400 Myr twin tidal tails as a case study. These tails have different colours of u - g = 1.05 ± 0.07 and r - i = 0.13 ± 0.07 for NGC 3256W, and u - g = 1.26 ± 0.07 and r - i = 0.26 ± 0.07 for NGC 3256E, indicating different stellar populations. These colours correspond to simple stellar population ages of 288-54+11 and 841-157+125 Myr for NGC 3256W and NGC 3256E, respectively, suggesting that NGC 3256W's diffuse light is dominated by stars formed after the interaction, while light in NGC 3256E is primarily from stars that originated in the host galaxy. Using a mixed stellar population model, we break our diffuse light into two populations: one at 10 Gyr, representing stars pulled from the host galaxies, and a younger component, whose age is determined by fitting the model to the data. We find similar ages for the young populations of both tails (195+0-13 and 170+44-70 Myr for NGC 3256W and NGC 3256E, respectively), but a larger percentage of mass in the 10 Gyr population for NGC 3256E (98-3+1 per cent versus 90-6+5 per cent). Additionally, we detect 31 star cluster candidates in NGC 3256W and 19 in NGC 2356E, with median ages of 141 and 91 Myr, respectively. NGC 3256E contains several young (<10 Myr), low-mass objects with strong nebular emission, indicating a small, recent burst of star formation.
UR - http://www.scopus.com/inward/record.url?scp=84988841173&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84988841173&partnerID=8YFLogxK
U2 - 10.1093/mnras/stw1294
DO - 10.1093/mnras/stw1294
M3 - Article
AN - SCOPUS:84988841173
SN - 0035-8711
VL - 461
SP - 36
EP - 50
JO - Monthly Notices of the Royal Astronomical Society
JF - Monthly Notices of the Royal Astronomical Society
IS - 1
ER -