• 천문학논총
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• 제30권2호
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• pp.499-502
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• 2015

Starburst galaxies have strong star formation activity and generate large scale outflows which eject a huge amount of gas mass. This process affects galaxy activity, and therefore, the detailed study of nearby starburst galaxies could provide valuable information for the study of distant ones. So far there have been only a few studies of galactic-scale molecular outflows due to the sensitivity limitation of telescopes. Our study provides two nearby examples, NGC 2146 and NGC 3628. We used Nobeyama Millimeter Array (NMA) CO(1-0) data, Chandra soft X-ray data, and NMA 3 mm data to study the kinematics of molecular outflows, their interaction with ionized outflows, and the star forming activity in the starburst region. We found that the gas ejected through molecular outflows is much more significant than that used to form stars.

• 천문학회지
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• 제39권2호
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• pp.31-40
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• 2006

Near-IR $H_2$ emission features in the northern region of the Orion A giant molecular cloud were observed in the $CO\;J\;=\;1\;{\rightarrow}\;0$ line in search of CO outflows. Out of the 30 sources surveyed, CO line wings were detected toward 28 positions, suggesting a strong correlation between $H_2$ jets and CO outflows. Blueshifted wings were detected toward 26 positions while redshifted wings were detected toward 15 positions, which suggests that there is a bias in the source selection. The bias is more severe in OMC 3 than in OMC 2. Since the protostars in OMC 3 are younger and more deeply embedded, the bias may be caused by the difference of extinction between blueshifted and redshifted outflows. Some physical parameters of the outflows were derived from the line profiles.

• KDI Journal of Economic Policy
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• 제36권4호
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• pp.33-69
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• 2014

본 논문은 펀드투자의 유입자금흐름과 유출자금흐름을 별도로 구분하여 결정요인을 실증분석하였다. 과거 성과, 펀드연령, 펀드규모, 판매보수 등 주요 요인의 자금흐름에 대한 효과는 유입자금과 유출자금 사이에 큰 차이가 있었다. 과거 성과와의 양(+)의 관계, 펀드연령과의 음(-)의 관계 등 순유입자금을 기반으로 한 기존 연구에서 확립된 실증 결과는 유출자금에 대해서는 반대로 나타났다. 특히 과거 성과의 유출자금과의 관계는 '처분효과(disposition effect)'의 존재를 시사하였다. 한편, '계열 펀드'와 '비계열 펀드'를 구분할 경우 판매보수의 유입자금과 유출자금에 대한 효과가 두 펀드그룹 사이에 상이하여, 판매사 간의 유인체계 차이가 펀드선택시장에서 중요한 요인인 것으로 나타났다. '처분효과'의 존재 등 본 논문에서 미국의 기존 연구와 다른 분석 결과가 얻어진 이유는 표본의 차이에 기인하였을 가능성이 있다.

• Journal of Astronomy and Space Sciences
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• 제18권1호
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• pp.1-6
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• 2001

In this paper we investigate the properties of advection-dominated accretion flows (ADAFs) in case that outflows carry away infalling matter with its angular momentum and energy. Positive Bernoulli number in ADAFs allow a fraction of the gas to be expelled in a form of outflows. The ADAFs are also unstable to convection. We present self-similar solutions for advection-dominated accretion flows in the presence of outflows from the accretion flows(ADIOS). The axisymmetric flow is treated in variables integrated over polar sections and the effects of outflows on the accretion flow are parameterized for possible configurations compatible with the one dimensional self-similar ADAF solution. We explicitly derive self-similar solutions of ADAFs in the presence of outflows and show that the strong outflows in the accretion flows result in a flatter density profile, which is similar to that of the convection-dominated accretion flows(CDAFs) in which convection transports the angular momentum inward and the energy outward. There two different versions of the ADAF model should show similar behaviors in X-ray spectrum to some extent. Even though the two models may show similar behaviors, they should be distinguishable due to different physical properties. We suggest that for a central object of which mass is known these two different accretion flow should have different X-ray flux value due to deficient matter in the wind model.

• 천문학회보
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• 제40권1호
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• pp.74.2-74.2
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• 2015

Strong outflows from active galactic nuclei (AGNs) may play a crucial role in galaxy evolution. Integral-field spectroscopy (IFS) is the most powerful tool to study the detailed kinematics of AGN outflows. We present the on-going optical 3D spectroscopic survey of ionized gas outflows. Type 2 AGN sample is uniquely selected from SDSS DR7 with a luminosity-limit (i.e., L[O III] > $10^{41.5}erg/s$) as well as strong kinematic signatures of ionized gas outflows ([O III] velocity shift > ~200 km/s or [O III] velocity dispersion (FWHM) > 1000 km/s), defining an extremely rare population (< ~0.5%). Thus, these AGNs with strong outflow signatures are one of the best suites for investigating AGN feedback. The IFS observations cover several kpc scales for the central region of the host galaxies, providing a detailed information of the kinematics and geometry of the gas outflows. In this contribution, we report the current status of the survey and the preliminary results on gas kinematics of 18 AGNs, based on the Magellan/IMACS-IFU and the VLT/VIMOS data.

• 천문학회보
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• 제40권2호
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• pp.32.3-33
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• 2015

There exist scaling relations that link the mass of supermassive black holes with both the velocity dispersion and the mass of the central stellar cusp of their host galaxies. This implies that these two components grow in tandem. Feedback from actively accreting supermassive black holes (AGN), in the form of multi-phase gas outflows, has been argued to be the agent of this co-evolution. Here we employ the powerful GMOS integral field spectroscopy unit on the 8.2m Gemini-North telescope to investigate ionized gas outflows of luminous Type 2 AGN in the local Universe (z<0.1). Our sample of 6 galaxies is drawn from the Sloan Digital Sky Survey (SDSS) and was selected based on their [OIII] dust-corrected luminosity (>1042 erg/s) and signatures of outflows in the [OIII] line profile of their spatially integrated SDSS spectra. These are arguably the best candidates to explore AGN feedback in action since they are < 1% of a large local type 2 AGN SDSS sample selected based on their [OIII] kinematics. We combine a careful spectral decomposition of the [OIII] and $H{\alpha}$ line profiles with spatial information on ~0.5kpc scales to understand the outflow kinematics and energetics in these objects. We find clear evidence for strong outflows in [OIII] and occasionally $H{\alpha}$ that are clearly driven by the ionizing radiation of the AGN. We kinematically and spatially decompose outflowing and rotating ionized gas components. We find [OIII] to be a better tracer of AGN outflows, while $H{\alpha}$ appears to be strongly affected by both stellar rotation and outflows induced by ongoing star formation. The observed kinematics and spatial distribution of the ionized gas imply a large opening angle for the outflow. Finally, we find the projected outflow velocity to decrease as a function of distance, while its dispersion shows a more complex structure with a potentially initially increasing trend (out to 0.5-1kpc distances).

• 천문학회보
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• 제42권1호
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• pp.38.2-38.2
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• 2017

We present the observational study toward the multiple outflows around $LkH{\alpha}$ 234 star formation region. The high-resolution, near-IR spectral mapping using the Immersion Grating Infrared Spectrograph (IGRINS) allowed us to distinguish at least four separate outflows with the molecular hydrogen ($H_2$) and forbidden iron ([Fe II]) emission lines. The outflow associated with the radio continuum source VLA 3B is detected in both H2 and [Fe II] emission, while the outflows driven by MM 1, VLA 2 sources were only detected in $H_2$, indicating the different physical conditions of outflows. We confirm the axis of VLA 3B jet, the position angle of ${\sim}240^{\circ}$. We firstly identified the redshifted, near-IR H2 outflow associated with VLA 2, which is coincident with the previous detections of $H_2O$ masers. From the $H_2$ line ratios, we interpret the gas properties of the shock excited blue- and redshifted components, and UV excited surrounding photodissociation region. We also discuss the origin of the high-velocity (|VLSR| > $150km\;s^{-1}$) $H_2$ emission.

• The Journal of Asian Finance, Economics and Business
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• 제10권1호
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• pp.79-89
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• 2023

The paper aims to investigate the asymmetric long-run and short-run relationships between inflation and remittance outflows in the Kingdom of Saudi Arabia (hereafter KSA) over the period 1971-2019 by using the Nonlinear Autoregressive Distributed Lag (NARDL) model. The statistical tests have supported the validity and stability of the model. The Wald F-test statistics confirm the existence of a long-run equilibrium relationship among the model variables; remittance outflows, positive (negative) shocks in inflation rates, investment, real GDP, and trade openness. Moreover, the empirical results confirm the existence of an asymmetric effect of the inflation rate on remittance outflows. The response of foreign workers to an increase in inflation rates differs from their response to a decrease in inflation rates. However, this asymmetric relationship between the increases/decreases in inflation and remittance outflows is significantly weak. The weakness of this relationship is due to the high marginal remittance propensity of migrant workers, which is explained by the low consumption propensity of foreign workers and their ability to adjust to the high cost of living due to inflation and the imposition of accompanying fees. Finally, the change in the inflation rate is not among the main factors influencing foreign remittance decisions in Saudi Arabia.

• 천문학논총
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• 제30권2호
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• pp.83-86
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• 2015

We present observational results characterizing molecular outflows from very low-mass objects in ${\rho}$ Ophiuchi and Taurus. Our results provide us with important implications that clarify the formation process of very low-mass objects.

• 천문학회보
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• 제43권1호
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• pp.37.2-37.2
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• 2018

The Wide-field Infrared Survey Explorer (WISE) mission has been efficient in selecting Active Galactic Nuclei (AGN) with high luminosities and large obscuration. According to the merger driven AGN powering scenarios, luminous and obscured AGN are in a stage where they go through feeding of gas accretion into the central black hole, and feedback to the host galaxy through outflows. We report the rest-frame UV-optical spectra of 11 Hot Dust Obscured Galaxies (Hot DOGs) at z~2, WISE color-selected to be extremely reddened AGN. A fraction of the targets show blueshifted and broadened [OIII] profiles indicative of ionized gas outflows. We present the occurrence and strength of the outflows, and discuss what impact these AGN activity could give on their hosts.