2018年IOAA数据分析第1题-产星星系中的尘埃与年轻恒星 - 版本历史

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@@ 第165行： / 第165行： @@
 .3. Under the previous assumption of the energy transfer process, the ratio of 𝐹FIR to 𝐹<sub>1600</sub> can be expressed as：
-$$
+<nowiki>$$
 \frac{F_{F I R}}{F_{1600}} \approx 10^{0.4 A_{1600}}-1
-$$
+$$</nowiki>
 Where 𝐹<sub>1600</sub> is the unattenuated flux and 𝐴<sub>λ</sub> is the dust absorption (in magnitudes) as a function of wavelength λ
@@ 第173行： / 第173行： @@
 (D1.3.1) (6 points) Express 𝐴<sub>1600</sub> as a function of IRX.
-(D1.3.2) (12 points) Based on Table 2 data and the function of 𝐴<sub>1600</sub>(𝐼𝑅𝑋) you derived above, plot the AE/CC−𝛽 diagram on graph paper and label it as Figure 3 and find a linear fit to the data. Write down your best-fit equation (i.e.𝐴<sub>1600</sub>=𝑎<sup>'</sup>⋅𝛽+𝑏<sup>'</sup>) by the side of your diagram.
+(D1.3.2) (12 points) Based on Table 2 data and the function of 𝐴<sub>1600</sub>(𝐼𝑅𝑋) you derived above, '''plot''' the AE/CC−𝛽 diagram on graph paper and label it as '''Figure 3''' and find a linear fit to the data. '''Write down''' your best-fit equation (i.e.𝐴<sub>1600</sub>=𝑎<sup>'</sup>⋅𝛽+𝑏<sup>'</sup>) by the side of your diagram.
-(D1.3.3) (2 points) If your linear model in (D1.3.2) is correct, what is the expected UV continuum slope 𝛽<sub>0</sub> of a dust-free galaxy?
+(D1.3.3) (2 points) If your linear model in (D1.3.2) is correct, what is the expected '''UV continuum slope''' 𝛽<sub>0</sub> of a dust-free galaxy?
 .4. After establishing the local relation between UV continuum slope and IRX, we could probably test this empirical law in the high-redshift universe. In 2016, researchers obtained an Atacama Large Millimeter / submillimeter Array (ALMA) observation of CR7, and the FIR continuum corresponded to a 3𝜎 upper limit of an FIR flux of 1.5×10<sup>-19</sup> Wm<sup>-2</sup>.
-(D1.4.1) (6 points) Calculate the IRX of CR7. Is it an upper limit or lower limit? Hint: here 𝐹<sub>1600</sub> should be written in the form of: 𝐹<sub>1600</sub>=𝜆<sub>0</sub>⋅𝑓<sub>1600</sub>
+(D1.4.1) (6 points) Calculate the '''IRX of CR7'''. Is it an upper limit or lower limit? Hint: here 𝐹<sub>1600</sub> should be written in the form of: 𝐹<sub>1600</sub>=𝜆<sub>0</sub>⋅𝑓<sub>1600</sub>
 where 𝜆<sub>0</sub>=160	nm        (1600	Å) and 𝑓<sub>1600</sub> is the observed flux in the rest-frame
-(D 1.4.2) (6 points) Is the current observation long enough to show any deviation of CR7 from the IRX−𝛽 relationship you just derived in the local universe? Please answer with [YES] or [NO] on the summary answer sheet, give the IRX difference and show the working used to calculate it on the answer sheet.
+(D 1.4.2) (6 points) Is the current observation long enough to show any deviation of CR7 from the IRX−𝛽 relationship you just derived in the local universe? '''Please answer with [YES] or [NO] on the summary answer sheet, give the IRX difference and show the working used to calculate it on the answer sheet.'''

@@ 第175行： / 第175行： @@
 (D1.3.2) (12 points) Based on Table 2 data and the function of 𝐴<sub>1600</sub>(𝐼𝑅𝑋) you derived above, plot the AE/CC−𝛽 diagram on graph paper and label it as Figure 3 and find a linear fit to the data. Write down your best-fit equation (i.e.𝐴<sub>1600</sub>=𝑎<sup>'</sup>⋅𝛽+𝑏<sup>'</sup>) by the side of your diagram.
- (D1.3.3) (2 points) If your linear model in (D1.3.2) is correct, what is the expected UV continuum slope 𝛽<sub>0</sub> of a dust-free galaxy?
+(D1.3.3) (2 points) If your linear model in (D1.3.2) is correct, what is the expected UV continuum slope 𝛽<sub>0</sub> of a dust-free galaxy?
 .4. After establishing the local relation between UV continuum slope and IRX, we could probably test this empirical law in the high-redshift universe. In 2016, researchers obtained an Atacama Large Millimeter / submillimeter Array (ALMA) observation of CR7, and the FIR continuum corresponded to a 3𝜎 upper limit of an FIR flux of 1.5×10<sup>-19</sup> Wm<sup>-2</sup>.

←上一版本		2019年9月12日 (四) 04:16的版本
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	(D1.3.1) (6 points) Express 𝐴<sub>1600</sub> as a function of IRX.		(D1.3.1) (6 points) Express 𝐴<sub>1600</sub> as a function of IRX.
		+
		+	(D1.3.2) (12 points) Based on Table 2 data and the function of 𝐴<sub>1600</sub>(𝐼𝑅𝑋) you derived above, plot the AE/CC−𝛽 diagram on graph paper and label it as Figure 3 and find a linear fit to the data. Write down your best-fit equation (i.e.𝐴<sub>1600</sub>=𝑎<sup>'</sup>⋅𝛽+𝑏<sup>'</sup>) by the side of your diagram.
		+
		+	(D1.3.3) (2 points) If your linear model in (D1.3.2) is correct, what is the expected UV continuum slope 𝛽<sub>0</sub> of a dust-free galaxy?
		+
		+	1.4. After establishing the local relation between UV continuum slope and IRX, we could probably test this empirical law in the high-redshift universe. In 2016, researchers obtained an Atacama Large Millimeter / submillimeter Array (ALMA) observation of CR7, and the FIR continuum corresponded to a 3𝜎 upper limit of an FIR flux of 1.5×10<sup>-19</sup> Wm<sup>-2</sup>.
		+
		+	(D1.4.1) (6 points) Calculate the IRX of CR7. Is it an upper limit or lower limit? Hint: here 𝐹<sub>1600</sub> should be written in the form of: 𝐹<sub>1600</sub>=𝜆<sub>0</sub>⋅𝑓<sub>1600</sub>
		+	where 𝜆<sub>0</sub>=160 nm (1600 Å) and 𝑓<sub>1600</sub> is the observed flux in the rest-frame
		+
		+	(D 1.4.2) (6 points) Is the current observation long enough to show any deviation of CR7 from the IRX−𝛽 relationship you just derived in the local universe? Please answer with [YES] or [NO] on the summary answer sheet, give the IRX difference and show the working used to calculate it on the answer sheet.

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	Where 𝐹<sub>1600</sub> is the unattenuated flux and 𝐴<sub>λ</sub> is the dust absorption (in magnitudes) as a function of wavelength λ		Where 𝐹<sub>1600</sub> is the unattenuated flux and 𝐴<sub>λ</sub> is the dust absorption (in magnitudes) as a function of wavelength λ
		+
		+	(D1.3.1) (6 points) Express 𝐴<sub>1600</sub> as a function of IRX.

←上一版本		2019年9月12日 (四) 04:04的版本
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	1.3. Under the previous assumption of the energy transfer process, the ratio of 𝐹FIR to 𝐹<sub>1600</sub> can be expressed as：		1.3. Under the previous assumption of the energy transfer process, the ratio of 𝐹FIR to 𝐹<sub>1600</sub> can be expressed as：

−	<br />	+	$$
		+	\frac{F_{F I R}}{F_{1600}} \approx 10^{0.4 A_{1600}}-1
		+	$$
		+
		+	Where 𝐹<sub>1600</sub> is the unattenuated flux and 𝐴<sub>λ</sub> is the dust absorption (in magnitudes) as a function of wavelength λ

@@ 第159行： / 第159行： @@
 (D1.2.2) (6 points) Quantify the '''dispersion''' (in ‘units’ of dex,  where 𝐟𝐨𝐫 𝐞𝐱𝐚𝐦𝐩𝐥𝐞,𝐥𝐨𝐠（𝟏𝟎<sup>𝟗</sup>）− 𝐥𝐨𝐠（𝟏𝟎<sup>𝟒</sup>）=𝟓 𝐝𝐞𝐱) between the observed IRX<sub>obs</sub> and predicted IRX<sub>pred</sub> using the following equation:
-$$
+<nowiki>$$
 \sigma=\sqrt{\frac{\sum\left(\Delta \operatorname{lRX} _{i}\right)^{2}}{N-1}}(\text { unit: dex }) \text { where } \Delta \operatorname{IRX} _{i}=\operatorname{IRX}_{\text {i,obs }}-\operatorname{IRX}_{\text {i,pred }}
-$$
+$$</nowiki>

@@ 第11行： / 第11行： @@
 (D1.1.1) (6 points) AB magnitude is a specific magnitude system. The AB magnitude is defined as:
-$$\mathrm{m}_{\mathrm{AB}}=-2.5 \log \frac{f_{v}}{3631 \mathrm{Jy}}$$
+<nowiki>$$\mathrm{m}_{\mathrm{AB}}=-2.5 \log \frac{f_{v}}{3631 \mathrm{Jy}}$$</nowiki>
 The AB magnitude of a typical galaxy is roughly constant in the UV band. What is the '''UV continuum slope''' of this kind of galaxy? (Hint:  𝑓<sub>λ</sub>∆𝜈=𝑓<sub>𝜆</sub>∆𝜆 )
@@ 第40行： / 第40行： @@
 .2. Under the assumption that dust grains in the galaxy absorb the energy of UV photons and re-emit it by blackbody radiation, the relation between the UV continuum slope (β), UV brightness (at 1600 Å) and FIR brightness could be established:
-$$
+<nowiki>$$
 \operatorname{IRX} \equiv \log \left(\frac{F_{F I R}}{F_{1600}}\right)=S(\beta)
-$$
+$$</nowiki>
 where 𝐹<sub>FIR</sub> is the observed far-infrared flux and 𝐹<sub>1600</sub> is the observed flux at rest-frame wavelength 160 nm ( 1600 Å) (The “flux” 𝐹λ is '''defined''' as 𝐹<sub>λ</sub> =𝜆⋅𝑓<sub>λ</sub>). Table 2 presents 20 measurements of 𝛽, 𝐹<sub>FIR</sub> and 𝐹<sub>1600</sub> in nearby galaxies (Meurer et al. 1999).
@@ 第157行： / 第157行： @@
 (D1.2.1) (14 points) Based on the data given in Table 2, '''plot''' the IRX−𝛽 diagram on graph paper and labelled as '''Figure 2''' and find a linear fit to the data. '''Write down''' your best-fit equation (i.e. IRX=𝑎⋅𝛽+𝑏) by the side of your diagram.
-<br />
+(D1.2.2) (6 points) Quantify the '''dispersion''' (in ‘units’ of dex,  where 𝐟𝐨𝐫 𝐞𝐱𝐚𝐦𝐩𝐥𝐞,𝐥𝐨𝐠（𝟏𝟎<sup>𝟗</sup>）− 𝐥𝐨𝐠（𝟏𝟎<sup>𝟒</sup>）=𝟓 𝐝𝐞𝐱) between the observed IRX<sub>obs</sub> and predicted IRX<sub>pred</sub> using the following equation:

←上一版本		2019年9月12日 (四) 01:28的版本
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	(D1.1.1) (6 points) AB magnitude is a specific magnitude system. The AB magnitude is defined as:		(D1.1.1) (6 points) AB magnitude is a specific magnitude system. The AB magnitude is defined as:

		+	$$\mathrm{m}_{\mathrm{AB}}=-2.5 \log \frac{f_{v}}{3631 \mathrm{Jy}}$$

	The AB magnitude of a typical galaxy is roughly constant in the UV band. What is the '''UV continuum slope''' of this kind of galaxy? (Hint: 𝑓<sub>λ</sub>∆𝜈=𝑓<sub>𝜆</sub>∆𝜆 )		The AB magnitude of a typical galaxy is roughly constant in the UV band. What is the '''UV continuum slope''' of this kind of galaxy? (Hint: 𝑓<sub>λ</sub>∆𝜈=𝑓<sub>𝜆</sub>∆𝜆 )