Kavli Affiliate: Gregory Herczeg
| First 5 Authors: Carlos Contreras Peña, Jeong-Eun Lee, Ho-Gyu Lee, Gregory Herczeg, Doug Johnstone
| Summary:
Long-lasting episodes of high accretion can strongly impact stellar and
planetary formation. However, the universality of these events during the
formation of young stellar objects (YSOs) is still under debate. Accurate
statistics of strong outbursts (FUors), are necessary to understand the role of
episodic accretion bursts. In this work, we search for a population of FUors
that may have gone undetected in the past because they either a) went into
outburst before the start of modern monitoring surveys and are now slowly
fading back into quiescence or b) are slow-rising outbursts that would not
commonly be classified as candidate FUors. We hypothesise that the light curves
of these outbursts should be well fitted by linear models with negative
(declining) or positive (rising) slopes. The analysis of the infrared light
curves and photometry of $sim$99000 YSO candidates from SPICY yields 717
candidate FUors. Infrared spectroscopy of 20 candidates, from both the
literature and obtained by our group, confirms that 18 YSOs are going through
long-term outbursts and identifies two evolved sources as contaminants. The
number of candidate FUors combined with previously measured values of the
frequency of FUor outbursts, yield average outburst decay times that are 2.5
times longer than the rise times. In addition, a population of outbursts with
rise timescales between 2000 and 5000 days must exist to obtain our observed
number of YSOs with positive slopes. Finally, we estimate a mean burst lifetime
of between 45 and 100 years.
| Search Query: ArXiv Query: search_query=au:”Gregory Herczeg”&id_list=&start=0&max_results=3