اشترك بالحزمة الذهبية واحصل على وصول غير محدود شمرا أكاديميا
تسجيل مستخدم جديدThe precession of the HH 111 flow in the infrared
50
0
0.0
(
0
)
تأليف
A. Noriega-Crespo
اسأل ChatGPT حول البحث
ﻻ يوجد ملخص باللغة العربية
We present Spitzer IRAC images of the HH 111 outflow, that show a wealth of condensations/knots in both jet and counterjet. Studying the positional distribution of these knots, we find very suggestive evidence of a mirror symmetric pattern in the jet/counterjet flow. We model this pattern as the result of an orbital motion of the jet source around a binary companion. From a fit of an analytic, ballistic model to the observed path of the HH 111 system, we find that the motion in a binary with two approx. 1 Msolar stars (one of them being the HH 111 source), in a circular orbit with a separation of approx. 186 AU would produce the mirror symmetric pattern seen in the outflow.
قيم البحث
اقرأ أيضاً
HH 175 is an isolated Herbig-Haro object seen towards the B35 cloud in the lambda Ori region. We use deep Subaru 8m interference filter images and Spitzer images to show that HH 175 is a terminal shock in a large collimated outflow from the nearby em
bedded source IRAS 05417+0907. The body of the eastern outflow lobe is hidden by a dense ridge of gas. The western outflow breaks out of the front of the cometary-shaped B35 cloud, carrying cloud fragments along, which are optically visible due to photoionization by the massive lambda Ori stars. The total extent of the bipolar outflow is 13.7 arcmin, which at the adopted distance of 415 pc corresponds to a projected dimension of 1.65 pc. The embedded source IRAS 05417+0907 is located on the flow axis approximately midway between the two lobes, and near-infrared images show it to be a multiple system of 6 sources, with a total luminosity of 31 Lsun. Millimeter maps in CO, 13CO, and C18O show that the B35 cloud is highly structured with multiple cores, of which the one that spawned IRAS 05417+0907 is located at the apex of B35. It is likely that the embedded source is the result of compression by an ionization-shock front driven by the lambda Ori OB stars.
We present an astrometry study of the radio source VLA 1 at the core of the HH 111 outflow using new data (2007) as well as archival observations (1992-1996). All data were taken at 3.6 cm with the Very Large Array in its most extended (A) configurat
ion. The source VLA 1 has undergone a dramatic morphological change, showing a one-sided knot ejection in the 2007 epoch. We also report on the detection of a 3.6 cm compact continuum source (VLA 3) located at (-10.6,98.7) from VLA 1. No significant absolute proper motions were found for VLA 1 and VLA 3 and the upper limits are consistent with those found for (embedded) radio sources in the Orion Nebula. We favor the interpretation that in the continuum at 3.6 cm we are observing two nearly perpendicular jets. HH 111 presents a new case of one-sided jet ejection in a young stellar object. The Galactic (or extragalactic) nature of VLA 3 remains unclear.
We present high angular resolution, high sensitivity 8.46 GHz (3.6 cm) radio continuum observations made toward the core of the HH~92 outflow with the Very Large Array in 2002-2003 and with the Expanded Very Large Array in 2011. We detect a group of
three compact sources distributed in a region 2$$ in extension and discuss their nature. We conclude that one of the objects (VLA 1) is the exciting source of the giant outflow associated with HH~92. In the case of HH~34 we present new 43.3 GHz (7 mm) observations that reveal the presence of a structure associated with the exciting source and elongated perpendicular to the highly collimated optical jet in the region. We propose that this 7 mm source is a circumstellar disk with radius of $sim$80 AU and mass of $sim$0.21 $M_odot$.
88 -
A. Noriega-Crespo Infrared Processing andn Analysis Center
, California Institute of Technology
2012
We present unpublished Spitzer IRAC observations of the HH 1/2 young stellar outflow processed with a high angular resolution deconvolution algorithm that produces sub-arcsecond (approx. 0.6 - 0.8) images. In the resulting mid-infrared images the opt
ically invisible counterjet is detected for the first time. The counterjet is approximately half as bright as the jet at 4.5 micron (the IRAC band that best traces young stellar outflows) and has a length of approx. 10. The NW optical jet itself can be followed back in the mid-IR to the position of the exciting VLA 1 source. An analysis of the IRAC colors indicates that the jet/counterjet emission is dominated by collisionally excited H2 pure rotational lines arising from a medium with a neutral Hydrogen gas density of 1000-2000 per cubic cm and a temperature of 1500 K. The observed jet/counterjet brightness asymmetry is consistent with an intrinsically symmetric outflow with extinction from a dense, circumstellar structure of 6 size (along the outflow axis), and with a mean visual extinction of Av=11 mag.
We present the results of Very Large Array NH$_{3}$ $(J,K)=(1,1)$ and $(2,2)$ observations of the HH 111/HH 121 protostellar system. HH 111, with a spectacular collimated optical jet, is one of the most well-known Herbig-Haro objects. We report the d
etection of a new source (NH$_{3}-$S) in the vicinity of HH 111/HH 121 ($sim$0.03 pc from the HH 111 jet source) in two epochs of the ammonia observations. This constitutes the first detection of this source, in a region which has been thoroughly covered previously by both continuum and spectral line interferometric observations. We study the kinematic and physical properties of HH 111 and the newly discovered NH$_{3}-$S. We also use HCO$^{+}$ and HCN $(J=4-3)$ data obtained with the James Clerk Maxwell Telescope and archival Atacama Large Millimeter/submillimeter Array $^{13}$CO, $^{12}$CO, and C$^{18}$O $(J=2-1)$, N$_2$D$^{+}$ $(J=3-2)$, and $^{13}$CS $(J=5-4)$ data to gain insight into the nature of NH$_{3}-$S. The chemical structure of NH$_3-$S shows evidence for selective freeze-out, an inherent characteristic of dense cold cores. The inner part of NH$_3-$S shows subsonic non-thermal velocity dispersions indicating a coherent core, while they increase in the direction of the jets. Archival near- to far-infrared data show no indication of any embedded source in NH$_3-$S. The properties of NH$_3-$S and its location in the infrared dark cloud suggest that it is a starless core located in a turbulent medium with turbulence induced by Herbig-Haro jets and associated outflows. More data is needed to fully understand the physical and chemical properties of NH$_3-$S and if/how its evolution is affected by nearby jets.
سجل دخول لتتمكن من نشر تعليقات
التعليقات
جاري جلب التعليقات
سجل دخول لتتمكن من متابعة معايير البحث التي قمت باختيارها
