STELLAR POPULATIONS OF BARRED QUIESCENT GALAXIES
STELLAR POPULATIONS OF BARRED QUIESCENT GALAXIES
复制标题
DOI：
10.1088/0004-637x/807/1/36
复制
发表时间：
2015-05
期刊：
影响因子：
--
通讯作者：
Edmond Cheung;C. Conroy;E. Athanassoula;E. Bell;A. Bosma;C. Cardamone;S. Faber;D. Koo;C. Lintott;K. Masters;T. Melvin;B. Simmons;K. Willett
中科院分区：
文献类型：
--
作者：
Edmond Cheung;C. Conroy;E. Athanassoula;E. Bell;A. Bosma;C. Cardamone;S. Faber;D. Koo;C. Lintott;K. Masters;T. Melvin;B. Simmons;K. Willett
从斯隆数字巡天（SDSS）中选择中心静止星系来创建高信噪比(约100 ？> Å−1)叠加光谱，最小的发射在线污染，我们准确和精确地模拟了棒和无棒静止盘状星系的中心恒星群。通过红移分离我们的样本，我们可以使用SDSS纤维的固定尺寸来模拟星系内不同半径的恒星群。在0.02时，SDSS光纤半径对应于≈1 kpc，这是经典凸起和盘状假凸起的典型半光半径。假设SDSS纤维主要覆盖了这些红移处的凸起，我们的分析表明，在棒状和非棒状静止盘状星系的凸起中，恒星群（即恒星年龄、[Fe/H]、[Mg/Fe]和[N/Fe]）没有显著差异。在固定的恒星质量下，以z = 0.020到z = 0.085的不同红移间隔对恒星群进行建模，得出了我们样本典型有效半径的一半左右的恒星群梯度的估计，假设在这≈1 Gyr时期内为零演化。我们发现，有棒和无棒静止盘状星系的方位平均梯度斜率没有明显差异。这些结果表明，条对静止盘状星系的化学演化并没有很大的影响。
Selecting centrally quiescent galaxies from the Sloan Digital Sky Survey (SDSS) to create high signal-to-noise ratio ( ≳ 100 ?> Å−1) stacked spectra with minimal emission-line contamination, we accurately and precisely model the central stellar populations of barred and unbarred quiescent disk galaxies. By splitting our sample by redshift, we can use the fixed size of the SDSS fiber to model the stellar populations at different radii within galaxies. At 0.02 , the SDSS fiber radius corresponds to ≈1 kpc, which is the typical half-light radii of both classical bulges and disky pseudobulges. Assuming that the SDSS fiber primarily covers the bulges at these redshifts, our analysis shows that there are no significant differences in the stellar populations, i.e., stellar age, [Fe/H], [Mg/Fe], and [N/Fe], of the bulges of barred versus unbarred quiescent disk galaxies. Modeling the stellar populations at different redshift intervals from z = 0.020 to z = 0.085 at fixed stellar masses produces an estimate of the stellar population gradients out to about half the typical effective radius of our sample, assuming null evolution over this ≈1 Gyr epoch. We find that there are no noticeable differences in the slopes of the azimuthally averaged gradients of barred versus unbarred quiescent disk galaxies. These results suggest that bars are not a strong influence on the chemical evolution of quiescent disk galaxies.